| MAXYGEN INC      Item 1A RISK FACTORS          This report contains forward-looking statements that involve risks and     uncertainties | 
    
      | Our  actual results could differ materially from those     anticipated in these forward-looking statements as a result of factors both     in and out of our control, including the risks faced by us described below     and elsewhere in this report | 
    
      | You should carefully consider the risks described below, together with all     of  the  other information included in this report, in considering our     business and prospects | 
    
      | The risks and uncertainties described below are not     the only ones facing our company | 
    
      | Additional risks and uncertainties not     presently known to us or that we currently                                            14     ______________________________________________________________________    [39]Table of Contents       deem immaterial also may impair our business operations | 
    
      | If any of the     following risks actually occur, our business could be harmed | 
    
      | In such case,     the trading price of our common stock could decline, and you may lose all or     part of your investment | 
    
      | We expect to continue to incur net losses     and may not achieve or maintain profitability | 
    
      | We have incurred losses since our inception, including a loss applicable to     common  stockholders  of  dlra35dtta2  million  in  2005,  before a positive     non-recurring adjustment of dlra16dtta6 million resulting from the cumulative     effect adjustment recorded as a result of the deconsolidation of Codexis,     and dlra33dtta7 million in 2003 | 
    
      | During 2004, we recognized income applicable to     common stockholders of dlra8dtta3 million, primarily due to the sale of Verdia,     but our loss from continuing operations was dlra49dtta1 million | 
    
      | Our loss from     continuing operations in 2005 was dlra35dtta1 million | 
    
      | As of December 31, 2005, we     had an accumulated deficit of dlra204dtta2 million | 
    
      | We expect to incur net losses     and negative cash flow from operating activities for at least the next     several  years | 
    
      | The  funded  research  portion  of one of our primary     collaborations, with Roche for our MAXY-alpha product candidates, ended in     December 2005 | 
    
      | To date, we have derived substantially all our revenues from     collaborations and grants and expect to derive a substantial majority of our     revenue from such sources for at least the next several years | 
    
      | Revenues from     collaborations and grants are uncertain because our existing agreements     generally have fixed terms and may be terminated under certain conditions,     and because our ability to secure future agreements will depend upon our     ability to address the needs of current and potential future collaborators | 
    
      | We  expect to spend significant amounts to fund the development of our     product candidates | 
    
      | As a result, we expect that our operating expenses will     exceed  revenues  in  the  near  term  and we do not expect to achieve     profitability during the next several years | 
    
      | If the time required for us to     achieve profitability is longer than we anticipate, we may not be able to     continue our business | 
    
      | We are an early stage company deploying unproven technologies | 
    
      | If we do not     develop  commercially  successful  products, we may be forced to cease     operations | 
    
      | You  must  evaluate  us in light of the uncertainties and complexities     affecting an early stage biotechnology company | 
    
      | We may not be successful in     the commercial development of products | 
    
      | Successful products will require     significant development and investment, including testing, to demonstrate     their safety and effectiveness before their commercialization | 
    
      | To date,     companies in the biotechnology industry have developed and commercialized     only a limited number of products | 
    
      | We have not proven our ability to develop     or commercialize any products | 
    
      | We, either alone or in conjunction with our     corporate collaborators, must conduct a substantial amount of additional     research and development before any regulatory authority will approve any of     our potential products | 
    
      | This research and development may not indicate that     our products are safe and effective, in which case regulatory authorities     may not approve them | 
    
      | Problems frequently encountered in connection with the     development  and  utilization of new and unproven technologies and the     competitive environment in which we operate could limit our ability to     develop commercially successful products | 
    
      | Our revenues, expenses and operating results are subject to fluctuations     that may cause our stock price to decline | 
    
      | Our revenues, expenses and operating results have fluctuated in the past and     are likely to do so in the future | 
    
      | These fluctuations could cause our stock     price to fluctuate significantly or decline | 
    
      | Some of the factors that could     cause our revenues, expenses and operating results to fluctuate include:           ·   termination of research contracts with collaborators or government     research grants, which may not be renewed or replaced;           ·   the success rate of our development or discovery efforts leading to     milestones and royalties;           ·   timing of licensing fees or the achievement of milestones under new or     existing licensing and collaborative arrangements;                                           15     ______________________________________________________________________    [40]Table of Contents         ·   timing of expenses, particularly with respect to contract     manufacturing, pre-clinical studies and clinical trials;           ·   the timing and willingness of collaborators to commercialize our     products, which would result in royalties to us; and           ·   general and industry specific economic conditions, which may affect     our collaborators’ research and development expenditures | 
    
      | A large portion of our expenses are relatively fixed, including expenses for     facilities, equipment and personnel | 
    
      | Accordingly, if revenues fluctuate     unexpectedly  due  to  unexpected  expiration of research contracts or     government research grants, failure to obtain anticipated new contracts or     other  factors, we may not be able to immediately reduce our operating     expenses | 
    
      | Failure to achieve anticipated levels of revenues could therefore     significantly harm our operating results for a particular fiscal period | 
    
      | Due to the possibility of fluctuations in our revenues and expenses, we     believe that quarter-to-quarter comparisons of our operating results are not     a good indication of our future performance | 
    
      | Our operating results in some     quarters  may  not  meet the expectations of stock market analysts and     investors | 
    
      | In that case, our stock price would likely decline | 
    
      | Our  revenues  are  substantially  dependent  on  a  limited number of     collaborative arrangements and government grants, and our inability to     maintain   existing  collaborations  or  grants  or  establish  future     collaborations or grants would adversely impact our revenues, financial     position and results of operation | 
    
      | We expect that substantially all of our revenue for the foreseeable future     will result from payments under our collaborative arrangements and from     government grants | 
    
      | We currently have one collaboration agreement, with Roche     for our MAXY-VII product candidates, and three government grants that are     expected to generate revenue in 2006 | 
    
      | If this collaboration agreement with     Roche  is not successful or the agreement or the government grants are     terminated and we are unable to enter into new collaboration agreements or     secure additional grants, our revenues, financial position and results of     operations would be materially adversely affected | 
    
      | Drug development is a long, expensive and uncertain process and may not     result in the development of any commercially successful products | 
    
      | The development of human therapeutic products is long and uncertain | 
    
      | Most     product candidates fail before entering clinical trials and most clinical     trials do not result in a marketed product | 
    
      | In addition, due to the nature     of  human therapeutic research and development, the expected timing of     product development and initiation of clinical trials and the results of     such development and clinical trials are uncertain and subject to change at     any point | 
    
      | This uncertainty may result in research delays, product candidate     failures and clinical trial delays and failures | 
    
      | Such delays and failures     could drastically reduce the price of our stock and our ability to raise     capital | 
    
      | Without sufficient capital, we would need to reduce operations and     could be forced to cease operations | 
    
      | In addition, we may determine that certain preclinical product candidates or     programs  do not have sufficient potential to warrant further funding | 
    
      | Accordingly,  we  may elect to terminate our programs for such product     candidates or programs at any time | 
    
      | If we terminate a preclinical program in     which we have invested significant resources, our financial condition and     results of operations may be adversely affected, as we will have expended     resources on a program that will not provide a return on our investment and     we will have missed the opportunity to have allocated those resources to     potentially more productive uses | 
    
      | Termination of such programs could cause     the price of our stock to drop significantly | 
    
      | Our potential products are subject to a lengthy and uncertain regulatory     process | 
    
      | If our potential products are not approved, we will not be able to     commercialize those products | 
    
      | The FDA must approve any therapeutic product or vaccine before it can be     marketed in the United States | 
    
      | Before we can file a new drug application or     biologic license application with the FDA, the product candidate                                           16     ______________________________________________________________________    [41]Table of Contents       must undergo extensive testing, including animal and human clinical trials,     which  can  take many years and require substantial expenditures | 
    
      | Data     obtained from such testing are susceptible to varying interpretations that     could delay, limit or prevent regulatory approval | 
    
      | In addition, changes in     regulatory  policy  for  product approval during the period of product     development and regulatory agency review of each submitted new application     or  product  license  application  may cause delays or rejections | 
    
      | The     regulatory process is expensive and time consuming | 
    
      | The regulatory agencies     of foreign governments must also approve our therapeutic products before the     products can be sold in those other countries | 
    
      | Because our potential products involve the application of new technologies     and may be based upon new therapeutic approaches, they may be subject to     substantial  review  by  government  regulatory  authorities and these     authorities may grant regulatory approvals more slowly for our products than     for products using more conventional technologies | 
    
      | We have not submitted an     application to the FDA or any other regulatory authority for any product     candidate,  and neither the FDA nor any other regulatory authority has     approved   any   therapeutic  product  candidate  developed  with  our     MolecularBreeding directed evolution platform for commercialization in the     United States or elsewhere | 
    
      | We may not be able to, or our collaborators may     not be able to, conduct clinical testing or obtain the necessary approvals     from the FDA or other regulatory authorities for our products | 
    
      | Even if we receive regulatory approval, this approval may entail limitations     on the indicated uses for which we can market a product | 
    
      | Further, once     regulatory approval is obtained, a marketed product and its manufacturer are     subject to continual review, and discovery of previously unknown problems     with a product or manufacturer may result in restrictions on the product,     manufacturer or manufacturing facility, including withdrawal of the product     from the market | 
    
      | In certain countries, regulatory agencies also set or     approve prices | 
    
      | The  manufacturing  of  our product candidates presents technological,     logistical and regulatory risks, each of which may adversely affect our     potential revenues | 
    
      | The manufacturing and manufacturing development of pharmaceuticals, and, in     particular, biologicals, are technologically and logistically complex and     heavily  regulated  by the FDA and other governmental authorities | 
    
      | The     manufacturing  and manufacturing development of our product candidates     present many risks, including, but not limited to, the following:           ·   before we can obtain approval of any of our products or product     candidates for the treatment of a particular disease or condition, we must     demonstrate to the satisfaction of the FDA and other governmental     authorities that the drug manufactured for the clinical trials is comparable     to the drug manufactured for commercial use and that the manufacturing     facility complies with applicable laws and regulations;           ·   it may not be technically feasible to scale up an existing     manufacturing process to meet demand or such scale-up may take longer than     anticipated; and           ·   failure to comply with strictly enforced GMP regulations and similar     foreign standards may result in delays in product approval or withdrawal of     an approved product from the market | 
    
      | Any of these factors could delay any clinical trials, regulatory submissions     or commercialization of our product candidates, entail higher costs and     result in our being unable to effectively sell any products | 
    
      | Our manufacturing strategy, which relies on third-party manufacturers,     exposes us to additional risks | 
    
      | We  do  not  currently have the resources, facilities or experience to     manufacture  any  product  candidates or potential products ourselves | 
    
      | Completion of any clinical trials and any commercialization of our products     will require access to, or development of, manufacturing facilities that     meet  FDA  standards or other regulatory requirements to manufacture a     sufficient supply of our potential products | 
    
      | We currently depend on third     parties for the scale up and manufacture of our product candidates for     preclinical and clinical purposes | 
    
      | If our third party manufacturers are     unable to manufacture preclinical or clinical supplies in a timely manner,     or are unable or                                           17     ______________________________________________________________________    [42]Table of Contents       unwilling to satisfy our needs or FDA or other regulatory requirements, it     could delay clinical trials, regulatory submissions and commercialization of     our potential products, entail higher costs and possibly result in our being     unable  to sell our products | 
    
      | In addition, technical problems or other     manufacturing delays could delay the advancement of potential products into     preclinical or clinical trials or result in the termination of development     of  particular  product  candidates,  adversely  affecting our product     development timetable, which in turn could adversely affect our stock price | 
    
      | In addition, failure of any third party manufacturers or us to comply with     applicable regulations, including pre- or post-approval inspections and the     GMP requirements of the FDA or other comparable regulatory agencies, could     result in sanctions being imposed on us | 
    
      | These sanctions could include     fines, injunctions, civil penalties, failure of regulatory authorities to     grant marketing approval of our products, delay, suspension or withdrawal of     approvals, license revocation, product seizures or recalls, operational     restrictions and criminal prosecutions, any of which could significantly and     adversely affect our business | 
    
      | If our collaborations are not successful, we may not be able to effectively     develop and market some of our products | 
    
      | Since we do not currently possess the resources necessary to develop and     commercialize multiple products, or the resources to complete all approval     processes that may be required for these potential products, we generally     seek to enter into collaborative arrangements to develop and commercialize     potential products | 
    
      | We have entered into collaborative agreements with other     companies to fund the development of new products for specific purposes | 
    
      | These contracts generally expire after a fixed period of time | 
    
      | If they are     not renewed or if we do not enter into new collaborative agreements, our     revenues  will  be  reduced  and  our  potential  products  may not be     commercialized | 
    
      | We have limited or no control over the resources that any collaborator may     devote to the development and commercialization of our potential products | 
    
      | Any of our present or future collaborators may not perform their obligations     as  expected | 
    
      | These  collaborators  may  delay  such  development  or     commercialization, breach or terminate their agreement with us or otherwise     fail to conduct their collaborative activities successfully and in a timely     manner | 
    
      | Further, our collaborators may elect not to develop potential     products arising out of our collaborative arrangements or devote sufficient     resources  to the development, manufacture, marketing or sale of these     products | 
    
      | If any of these events occur, we may not be able to develop or     commercialize our potential products | 
    
      | In  particular,  we  have  entered  into agreements with Roche for the     co-development and commercialization of two of our lead product candidates,     MAXY-alpha and MAXY-VII The failure of Roche to perform its obligations     under either agreement, our failure to perform our obligations under either     agreement  or  to effectively manage our relationship with Roche, or a     material contractual dispute with Roche under either agreement would have a     material adverse effect on our prospects and financial results | 
    
      | We  conduct  proprietary research programs, and any conflicts with our     collaborators or any inability to commercialize products resulting from this     research could harm our business | 
    
      | An important part of our strategy involves conducting proprietary research     programs | 
    
      | As a result, we may pursue opportunities in fields that could     conflict with those of our collaborators | 
    
      | Moreover, disagreements with our     collaborators could develop over rights to our intellectual property | 
    
      | Any     conflict with our collaborators could reduce our ability to obtain future     collaboration  agreements  and negatively impact our relationship with     existing collaborators, which could reduce our revenues | 
    
      | Certain of our collaborators could become our competitors in the future | 
    
      | Our     collaborators could develop competing products, preclude us from entering     into collaborations with their competitors, fail to obtain timely regulatory     approvals, terminate their agreements with us prematurely or fail to devote     sufficient resources to                                           18     ______________________________________________________________________    [43]Table of Contents       allow the development and commercialization of our products | 
    
      | Any of these     developments could harm our product development efforts | 
    
      | In some cases, our collaborators already market a product that could be     competitive with the product(s) that we are collaborating with them on for     an improved version, and could conduct their operations in a manner that     discriminates against the product that we developed | 
    
      | We  will  either commercialize products resulting from our proprietary     programs  directly or through licensing to other companies | 
    
      | We have no     experience in manufacturing or marketing, and we currently do not have the     resources or capability to manufacture products on a commercial scale | 
    
      | In     order for us to commercialize these products directly, we would need to     develop, or obtain through outsourcing arrangements, the capability to     manufacture,  market  and  sell  products, each of which could require     significant capital investment | 
    
      | We do not have these capabilities, and we     may not be able to develop or otherwise obtain the requisite manufacturing,     marketing  and  sales  capabilities | 
    
      | If we are unable to successfully     commercialize products resulting from our proprietary research efforts, we     will continue to incur losses | 
    
      | Any inability to adequately protect our proprietary technologies could harm     our competitive position | 
    
      | Our  success  will depend in part on our ability to obtain patents and     maintain  adequate  protection  of  our  intellectual property for our     technologies and products in the United States and other countries | 
    
      | If we do     not adequately protect our intellectual property, competitors may be able to     practice our technologies and erode our competitive advantage | 
    
      | The laws of     some foreign countries do not protect proprietary rights to the same extent     as  the laws of the United States, and many companies have encountered     significant problems in protecting their proprietary rights in these foreign     countries | 
    
      | These problems can be caused by, for example, a lack of rules and     processes allowing for meaningfully defending intellectual property rights | 
    
      | We will be able to protect our proprietary rights from unauthorized use by     third parties only to the extent that our proprietary technologies are     covered by valid and enforceable patents or are effectively maintained as     trade secrets | 
    
      | The patent positions of biopharmaceutical and biotechnology     companies, including our patent positions, are often uncertain and involve     complex legal and factual questions | 
    
      | We apply for patents covering our     technologies and potential products as we deem appropriate | 
    
      | However, we may     not obtain patents on all inventions for which we seek patents, and any     patents  we  obtain  may be challenged and may be narrowed in scope or     extinguished as a result of such challenges | 
    
      | Our existing patents and any     future patents we obtain may not be sufficiently broad to prevent others     from practicing our technologies or from developing competing products | 
    
      | Enforcement of our patents against infringers could require us to expend     significant amounts with no assurance that we would be successful in any     litigation | 
    
      | Others  may  independently develop similar or alternative     technologies or design around our patented technologies or products | 
    
      | In     addition, others may challenge or invalidate our patents, or our patents may     fail to provide us with any competitive advantages | 
    
      | We rely upon trade secret protection for our confidential and proprietary     information | 
    
      | We have taken security measures to protect our proprietary     information | 
    
      | These measures may not provide adequate protection for our     trade secrets or other proprietary information | 
    
      | We seek to protect our     proprietary information by entering into confidentiality agreements with     employees,  collaborators  and  consultants | 
    
      | Nevertheless, employees,     collaborators or consultants may still disclose or misuse our proprietary     information,  and we may not be able to meaningfully protect our trade     secrets | 
    
      | In  addition, others may independently develop substantially     equivalent proprietary information or techniques or otherwise gain access to     our trade secrets | 
    
      | Litigation  or other proceedings or third party claims of intellectual     property infringement could require us to spend time and money and could     require us to shut down some of our operations | 
    
      | Our ability to develop products depends in part on not infringing patents or     other proprietary rights of third parties, and not breaching any licenses     that we have entered into with regard to our technologies and products | 
    
      | 19     ______________________________________________________________________    [44]Table of Contents       Others have filed, and in the future are likely to file, patent applications     covering genes or gene fragments or corresponding proteins or peptides that     we may wish to utilize with our proprietary technologies, or products that     are  similar to products developed with the use of our technologies or     alternative  methods  of  generating  gene  diversity | 
    
      | If these patent     applications  result in issued patents and we wish to use the patented     technology, we would need to obtain a license from the third party, which     may not be available on acceptable terms, if at all | 
    
      | Third parties may assert that we are employing their proprietary technology     without authorization | 
    
      | In particular, our efforts to develop improved,     next-generation protein pharmaceuticals could lead to allegations of patent     infringement by the parties commercializing other versions of such proteins | 
    
      | In addition, third parties may obtain patents in the future and claim that     our technologies or product candidates infringe these patents | 
    
      | We could     incur  substantial  costs  and  diversion of the time and attention of     management and technical personnel in defending ourselves against any of     these claims or enforcing our patents or other intellectual property rights     against others | 
    
      | Furthermore, parties making claims against us may be able to     obtain injunctive or other equitable relief that could effectively block our     ability to further develop, commercialize and sell products | 
    
      | In addition, in     the  event of a successful claim of infringement against us, we may be     required to pay damages and obtain one or more licenses from third parties | 
    
      | We may not be able to obtain these licenses at a reasonable cost, if at all | 
    
      | In that event, we could encounter delays in product introductions while we     attempt to develop alternative methods or products, or be required to cease     commercializing affected products | 
    
      | We  monitor the public disclosures of other companies operating in our     industry regarding their technological development efforts | 
    
      | If we determine     that these efforts violate our intellectual property or other rights, we     intend to take appropriate action, which could include litigation | 
    
      | Any     action we take could result in substantial costs and diversion of management     and technical personnel | 
    
      | Furthermore, the outcome of any action we take to     protect our rights may not be resolved in our favor | 
    
      | Budget or cash constraints may force us to delay or terminate our efforts to     develop certain products and could prevent us from executing our business     plan,  meeting our stated timetables and commercializing our potential     products as quickly as possible | 
    
      | Because we are an emerging company with limited resources, and because the     research and development of pharmaceuticals is a long and expensive process,     we must regularly assess the most efficient allocation of our research and     development resources | 
    
      | Accordingly, we may choose to delay or terminate our     research  and development efforts for a promising product candidate to     allocate those resources to another program, which could cause us to fall     behind  our  initial  timetables  for  development and prevent us from     commercializing product candidates as quickly as possible | 
    
      | As a result, we     may not be able to fully realize the value of some of our product candidates     in a timely manner, since they will be delayed in reaching the market, or     may not reach the market at all | 
    
      | We  are  continuing our efforts to contain costs | 
    
      | On June 16, 2005, we     announced a reduction in force of approximately 16prca of our personnel, across     both our research and administrative functions | 
    
      | This reduction in force was     a part of our efforts to focus our resources on product development | 
    
      | As a     result of the reduction in force, we recorded termination costs of dlra807cmam000     during 2005, comprised primarily of involuntary termination benefits | 
    
      | We     continue to believe strict cost containment in the near term is essential if     our current funds are to be sufficient to allow us to continue our currently     planned operations | 
    
      | We assess market conditions on an ongoing basis and plan     to take appropriate actions as required | 
    
      | However, we may not be able to     effectively contain our costs and achieve an expense structure commensurate     with our business activities and revenues | 
    
      | As a result, we have inadequate     levels of cash for future operations or for future capital requirements,     which could significantly harm our ability to operate the business | 
    
      | We may need additional capital in the future | 
    
      | If additional capital is not     available, we may have to curtail or cease operations | 
    
      | We anticipate that existing cash and cash equivalents and income earned     thereon, together with anticipated revenues from collaborations and grants,     will enable us to maintain our currently planned operations for at least                                           20     ______________________________________________________________________    [45]Table of Contents       the next twelve months | 
    
      | However, our current plans and assumptions may     change,  and  our  capital requirements may increase in future periods     depending on many factors, including payments received under collaborative     agreements  and  government  grants,  the  progress  and  scope of our     collaborative and independent research and development projects, the extent     to which we advance products into clinical trials with our own resources,     the effect of any acquisitions, and the filing, prosecution and enforcement     of  patent claims | 
    
      | Changes may also occur that would consume available     capital resources significantly sooner than we expect | 
    
      | We have no committed sources of capital and do not know whether additional     financing will be available when needed, or, if available, that the terms     will be favorable to us or our stockholders | 
    
      | If additional funds are not     available, we may be forced to delay or terminate research or preclinical     development programs, clinical trials, if any, or the commercialization of     products,  if  any,  resulting from our technologies, curtail or cease     operations or obtain funds through collaborative and licensing arrangements     that may require us to relinquish commercial rights or potential markets, or     grant licenses on terms that are not favorable to us | 
    
      | If adequate funds are     not available, we will not be able to successfully execute our business plan     or continue our business | 
    
      | Many potential competitors who have greater resources and experience than we     do may develop products and technologies that make ours obsolete | 
    
      | The biotechnology industry is characterized by rapid technological change,     and  the area of gene research is a rapidly evolving field | 
    
      | Our future     success will depend on our ability to maintain a competitive position with     respect to technological advances | 
    
      | Rapid technological development by others     may result in our products and technologies becoming obsolete | 
    
      | We face, and will continue to face, intense competition from both large and     small biotechnology companies, as well as academic and research institutions     and  government agencies, that are pursuing competing technologies for     modifying DNA and proteins | 
    
      | These companies and organizations may develop     technologies  that  are alternatives to our technologies | 
    
      | Further, our     competitors in the protein optimization field may be more effective at     implementing their technologies to develop commercial products | 
    
      | Some of     these competitors have entered into collaborations with leading companies     within our target markets to produce commercial products | 
    
      | Any  products that we develop through our technologies will compete in     multiple, highly competitive markets may fail to achieve market acceptance,     which would impair our ability to become profitable | 
    
      | Most of the companies     and organizations competing with us in the markets for such products have     greater capital resources, research and development and marketing staff and     facilities and capabilities, and greater experience in modifying DNA and     proteins,  obtaining  regulatory approvals, manufacturing products and     marketing | 
    
      | Our  product  candidates, even if approved by the FDA or a     comparable foreign regulatory agency, may fail to achieve market acceptance,     which would impair our ability to become profitable | 
    
      | Accordingly,  our  competitors may be able to develop technologies and     products more easily, which would render our technologies and products and     those of our collaborators obsolete and noncompetitive | 
    
      | Legislative actions, recent and potential new accounting pronouncements and     higher compliance costs are likely to adversely impact our future financial     position and results of operations | 
    
      | Recent  changes  in  financial accounting standards may cause adverse,     unexpected earnings fluctuations and will adversely affect our reported     results of operations | 
    
      | For example, on December 16, 2004, the Financial     Accounting Standards Board, or FASB, issued FASB Statement Nodtta 123 (revised     2004), “Share-Based Payment,” or SFAS 123(R), which requires all share-based     payments to employees, including grants of employee stock options, to be     recognized in the income statement based at their fair values | 
    
      | We adopted     SFAS 123(R) as of January 1, 2006 and we expect the implementation of SFAS     123(R)’s fair value method to have a significant impact on our results of     operations | 
    
      | Such charges will significantly increase our net loss and delay     our  ability  to achieve profitability | 
    
      | The magnitude of the impact of     expensing stock-based compensation will depend in part                                           21     ______________________________________________________________________    [46]Table of Contents       upon  the  timing and amount of future equity compensation awards | 
    
      | New     accounting pronouncements and varying interpretations of such pronouncements     have occurred with frequency in the recent past and may occur in the future | 
    
      | In addition, we may make changes in our accounting policies in the future | 
    
      | Compliance with changing regulations regarding corporate governance and     public disclosure will also result in additional expenses | 
    
      | Changing laws,     regulations  and standards relating to corporate governance and public     disclosure,  including  the Sarbanes-Oxley Act of 2002 and related SEC     regulations and Nasdaq National Market listing requirements, have created     uncertainty for companies such as ours and compliance costs are increasing     as a result of this uncertainty and other factors | 
    
      | We are committed to     maintaining high standards of corporate governance and public disclosure | 
    
      | As     a result, we intend to invest all reasonably necessary resources to comply     with  evolving standards, and this investment will result in increased     general and administrative expenses and may cause a diversion of management     time  and  attention  from revenue-generating activities to compliance     activities | 
    
      | If  we  do not attract and retain key employees, our business could be     impaired | 
    
      | To be successful and achieve our objectives, we must attract and retain     qualified scientific and management personnel | 
    
      | If we are unsuccessful in     attracting and retaining qualified personnel, particularly at the management     level, our business could be impaired | 
    
      | We have been successful in hiring and     retaining  key  personnel  in  the  past; however, we face significant     competition for experienced, management level personnel | 
    
      | Although we believe     have  been successful in attracting and retaining qualified personnel,     competition  for  experienced management personnel and scientists from     numerous companies and academic and other research institutions may limit     our ability to do so in the future on acceptable terms | 
    
      | Failure to attract     and  retain personnel could prevent us from pursuing collaborations or     developing our products or core technologies | 
    
      | The operation of international locations may increase operating expenses and     divert management attention | 
    
      | We  conduct  certain of our operations through Maxygen ApS, our Danish     subsidiary | 
    
      | Operation  as an international entity requires additional     management attention and resources | 
    
      | We have limited experience in operating     internationally  and  in  conforming our operations to local cultures,     standards and policies | 
    
      | The costs of operating internationally are expected     to continue to exceed our international revenues, if any, for at least the     next  several years | 
    
      | As we continue to operate internationally, we are     subject to risks of doing business internationally, including the following:           ·   regulatory requirements that may limit or prevent the offering of our     products in local jurisdictions;           ·   local legal and governmental limitations on company-wide employee     benefit practices, such as the operation of our employee stock option plan     in local jurisdictions;           ·   government limitations on research and/or research involving     genetically engineered products or processes;           ·   difficulties in staffing and managing foreign operations;           ·   currency exchange risks; and           ·   potentially adverse tax consequences | 
    
      | Acquisitions could result in dilution, operating difficulties and other     harmful consequences | 
    
      | If appropriate opportunities present themselves, we may acquire businesses     or technologies that complement our capabilities | 
    
      | The process of integrating     any  acquisition  may  create  unforeseen  operating  difficulties and     expenditures and is itself risky | 
    
      | The areas where we may face difficulties     include:           ·   diversion of management time (both ours and that of the acquired     company) from focus on operating the businesses to issues of integration     during the period of negotiation through closing and further diversion of     such time after closing;                                           22     ______________________________________________________________________    [47]Table of Contents         ·   decline in employee morale and retention issues resulting from changes     in compensation, reporting relationships, future prospects, or the direction     of the business;           ·   the need to integrate each company’s accounting, management     information, human resource and other administrative systems to permit     effective management and the lack of control if such integration is delayed     or not implemented; and           ·   the need to implement controls, procedures and policies appropriate     for a larger public company in companies that before acquisition had been     smaller, private companies | 
    
      | We do not have extensive experience in managing this integration process | 
    
      | Moreover, the anticipated benefits of any or all of these acquisitions may     not be realized | 
    
      | Future acquisitions could result in potentially dilutive issuances of equity     securities, the incurrence of debt, contingent liabilities or amortization     expenses related to intangible assets, any of which could harm our business | 
    
      | Future acquisitions may require us to obtain additional equity or debt     financing, which may not be available on favorable terms or at all | 
    
      | Even if     available, this financing may be dilutive | 
    
      | Our stock price has been, and may continue to be, extremely volatile, and an     investment in our stock could decline in value | 
    
      | The trading prices of life science company stocks in general, and ours in     particular, have experienced significant price fluctuations in the last     several years | 
    
      | During the twelve-month period ended December 31, 2005, the     price of our common stock on the Nasdaq National Market ranged from dlra6dtta49 to     dlra12dtta64 | 
    
      | The valuations of many life science companies without product     revenues and earnings, including ours, are based on valuation standards such     as price to sales ratios and progress in product development or clinical     trials | 
    
      | Trading prices based on these valuations may not be sustained | 
    
      | Any     negative change in the public’s perception of the prospects of biotechnology     or life science companies could depress our stock price regardless of our     results of operations | 
    
      | Other broad market and industry factors may decrease     the trading price of our common stock, regardless of our performance | 
    
      | In     addition, our stock price could be subject to wide fluctuations in response     to factors including the following:           ·   our failure to meet our publicly announced revenue and/or expense     projections and/or product development timetables;           ·   adverse results or delays in preclinical development or clinical     trials;           ·   any decisions to discontinue or delay development programs or clinical     trials;           ·   announcements of new technological innovations or new products by us     or our competitors;           ·   conditions or trends in the biotechnology and life science industries;           ·   changes in the market valuations of other biotechnology or life     science companies;           ·   developments in domestic and international governmental policy or     regulations;           ·   announcements by us or our competitors of significant acquisitions,     strategic partnerships, joint ventures or capital commitments;           ·   developments in or challenges relating to patent or other proprietary     rights; and           ·   sales of our common stock or other securities in the open market | 
    
      | In the past, stockholders have often instituted securities class action     litigation after periods of volatility in the market price of a company’s     securities | 
    
      | If a stockholder files a securities class action suit against     us, we could incur substantial legal fees and our management’s attention and     resources would be diverted from operating our business to respond to the     litigation | 
    
      | 23     ______________________________________________________________________    [48]Table of Contents       Substantial sales of shares may adversely impact the market price of our     common stock | 
    
      | If our stockholders sell substantial amounts of our common stock, including     shares issued upon the exercise of outstanding options, the market price of     our common stock may decline | 
    
      | Our common stock trading volume is low and     thus the market price of our common stock is particularly sensitive to     trading volume | 
    
      | Our low trading volume may also make it more difficult for     us to sell equity or equity related securities in the future at a time and     price that we deem appropriate | 
    
      | Significant sales of our common stock may     adversely impact the then-prevailing market price of our common stock | 
    
      | Some of our existing stockholders can exert control over us, and may not     make decisions that are in the best interests of all stockholders | 
    
      | As of December 31, 2005, our executive officers and directors, together with     GlaxoSmithKline plc, controlled approximately 28prca of our outstanding common     stock | 
    
      | As  a  result,  these  stockholders, if they act together, and     GlaxoSmithKline plc, which owns approximately 18prca of our outstanding common     stock, by itself, could exert a significant degree of influence over our     management and affairs and over matters requiring stockholder approval,     including the election of directors and approval of significant corporate     transactions | 
    
      | In addition, this concentration of ownership may delay or     prevent a change in control of our company and might affect the market price     of our common stock, even when a change may be in the best interests of all     stockholders | 
    
      | In addition, the interests of this concentration of ownership     may  not  always coincide with our interests or the interests of other     stockholders and accordingly, they could cause us to enter into transactions     or agreements that we would not otherwise consider | 
    
      | This concentration of     ownership could also depress our stock price |