Document:

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                                                                   EXHIBIT 10.20

CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                              TECHNOLOGY AGREEMENT

                      GENERATION OF KNOCKOUT MOUSE STRAINS

                                     between

                                 DELTAGEN, INC.
                                1031 Bing Street
                              San Carlos, CA 94070

                                       and

                                MERCK & CO, INC.
                                 One Merck Drive
                                  P.O. Box 100
                    Whitehouse Station, New Jersey 08889-0100

WHEREAS,  Deltagen,  Inc.  ("Deltagen")  and Merck  ("Merck"),
(collectively,  "Parties")  seek to  collaborate in scientific research
related to generation of Knockout Mouse strains;

WHEREAS, Deltagen has knowledge and experience in research and generation of
Knockout Mice; and

WHEREAS, Merck wishes to obtain Knockout Mice generated by Deltagen according
to specifications agreed by the Parties.

1.       DEFINITIONS

As used in this.Agreement the following terms shall have the meanings as
specified:

1.1      "Merck Affiliate" shall mean (i) any corporation or business entity of
         which fifty percent (50%) or more of the securities or other ownership
         interest representing the equity, the voting stock or general
         partnership interest are owned, controlled or held, directly or
         indirectly, by Merck; or (ii) any corporation or business entity which,
         directly or indirectly, owns, controls, or holds 50 percent (50%) (or
         the maximum ownership permitted by law) or more of the securities or
         other ownership interest representing the equity, the voting stock or,
         if applicable, the general partnership interest, of Merck.

1.2      "Effective Date" shall mean the date of the signature of the
         representative of the last of the Parties to execute this
         Agreement.

1.3      "Joint Patents" shall mean all patent and patent applications,
         worldwide, for subject matter which is jointly developed during the
         course of this Agreement by both Deltagen and Merck and which is useful
         or necessary in the generation of the Knockout Mice under this
         Agreement.

1.4      "Joint Technology" shall mean all know-how and technology related to
         the generation of Knockout Mice as well as biological, molecular
         biological and genetic work and technology in each case, which is
         developed jointly hereunder by Deltagen and Merck and which is useful
         in the generation of the Knockout Mice under this Agreement.

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1.5      "Knockout Mice" shall mean a line of chimeric mice developed for and
         delivered to Merck as set forth in Article 2 below, having a Standard
         Mutation wherein such mice transmit the Standard Mutation, in the form
         of a mutant allele, through the germ line.

1.6      "Knockout Mouse Project" shall mean the creation, testing and
         generation, by Deltagen, of Knockout Mice.

1.7      "Deltagen Patents" shall mean any and all patents and patent
         applications, worldwide, owned by Deltagen with respect to Knockout
         Mice.

1.8      "Deltagen Technology" shall mean technology related to the generation
         of Knockout Mice or other animals, as well as biological, molecular
         biological and genetic work and technology developed solely by Deltagen
         with respect to Knockout Mice delivered to Merck under this Agreement.

1.9      "Merck Patents" shall mean any and all patents and patent applications,
         world-wide, owned by Merck, with respect to * * * .

1.10     "Merck Technology" shall mean technology related to * * *, as well
         as * * * work and technology developed solely by Merck * * *.

1.11     "Milestone Payments" shall mean those payments set forth at Appendix A
         attached hereto.

1.12     "Standard Mutation' `shall mean the interruption or deletion in a
         portion of a single, specified gene by * * *.

1.13     "Non-Standard Mutations" shall mean any mutation other than a "Standard
         Mutation." Examples of non-standard mutations include* * *.
         Non-standard mutations also includes * * *.

1.14     "Standard Procedure" shall mean the set of procedures described in
         Appendix A, with respect to "Milestone 1" through "Milestone 5."

2.       RESEARCH AND WORK TO BE CONDUCTED

2.1      Deltagen shall conduct one or more Knockout Mouse Projects at the
         request of Merck on the terms and conditions of this Agreement. Merck
         will request Deltagen in writing to begin work on each Knockout Mouse
         project to be conducted under this Agreement, such written notice to be
         provided to Deltagen by an authorized representative of Merck in the
         form set forth in Appendix B. Deltagen shall have the right to evaluate
         such request and the information provided to Deltagen by Merck under
         Section 2.3 below, to determine whether such requested Knockout Mouse
         project is feasible. If, after good faith discussion with Merck,
         Deltagen reasonably determines that such project is not technically
         feasible, within the parameters of Appendix A, Deltagen shall so advise
         Merck in writing and shall not be required to undertake such project.

2.2      For each Knockout Mouse Project, Deltagen will use reasonable efforts
         to complete each Milestone in a timely fashion, as defined in Appendix
         A.

2.3      Deltagen shall undertake up to * * * Knockout Mice Projects according
         to the terms and conditions set forth in this Agreement. To initiate
         each Knockout Mouse project the parties agree to undertake, Deltagen
         and Merck will establish a timetable for each project Milestone, and
         Merck shall:

* * * Confidential material redacted and separately filed with the Commission.

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         2.3.1    Identify to Deltagen in writing each Knockout Mouse Project
                  to be initiated;

         2.3.2    Disclose in writing to Deltagen * * * useful in completing
                  Milestone 1 with respect to each Knockout Mouse Project, as
                  defined at Appendix A;

         2.3.3    Consult with Deltagen to identify the specific region of the
                  gene Merck desires to have deleted for such Knockout Mouse
                  Project;

         2.3.4    Transfer to Deltagen * * * may be * * *; and

         2.3.5    Identify and notify Deltagen in writing of the specific gene
                  sequence for each Knockout Mouse Project for which Deltagen is
                  requested by Merck to produce a Knockout Mouse. Merck shall be
                  solely responsible for identifying and notifying Deltagen in
                  writing of the specific gene sequence for each Knockout Mouse
                  project.

2.4      For purposes of the schedule set forth in Appendix A, each Knockout
         Mouse Project conducted hereunder shall commence fifteen (15) days
         after Deltagen's receipt from Merck of all information and materials
         set forth in Section 2.3 relating to such Knockout Mouse Project.

2.5      Each Knockout Mouse Project shall be deemed complete upon Deltagen's
         completion of Milestone 5 (see Appendix A) and Deltagen's delivery
         after the birth of the first generation of Knockout Mice of at least
         * * *. Deltagen, for a period of six (6) months following the
         completion of each Milestone 5 for each Knockout Mouse Project, shall
         retain a small backup colony of * * * from such project consisting of
         * * * for each Knockout Mouse Project). With respect to such backup
         colonies of Knockout Mice, Merck shall for a period not to exceed six
         (6) months following completion of Milestone 5 pay to Deltagen* * *.
         At Merck's request, Deltagen will transfer the mice to Merck. All
         reasonable transportation and transfer costs shall be paid by Merck.
         If Merck does not request transfer within the six month period,
         Deltagen, following Deltagen's written notification to Merck, shall
         dispose of the mice in accordance with all applicable laws and
         regulations.

2.6      Deltagen shall use reasonable efforts to * * * and to generate Knockout
         Mice under each Knockout Mouse project according to the specification
         of Merck as set forth in Section 2.3 above.

2.7      Deltagen shall, at all times in its animal care and handling activities
         related to this Agreement, comply with all applicable Federal, State
         and local laws and regulations, and assure that Deltagen animal
         facilities meet or exceed minimum accreditation standards including,
         but not limited to those established by * * * and the * * * for the
         Care and Use of Laboratory Animals. Deltagen shall have sole liability
         for the care and handling of the Knockout Mice until they are delivered
         to Merck in accordance with Section 7.6 below.

3.       PAYMENTS

3.1      Within thirty (30)days afterthe Effective Date, Merck shall payto
         Deltagen * * * for the * * * calculated in accordance with Appendix
         A. Such payment shall be * * * Milestones as set forth in Appendix A.

3.2      Merck shall pay to Deltagen for each Milestone completed by Deltagen:

* * * Confidential material redacted and separately filed with the Commission.

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         3.2.1    The Milestone Payments set forth in Appendix A are for all
                  Knockout Mouse Projects wherein a * * * is requested by Merck
                  under Section 2.3 above, so long as the Project is initiated
                  during the term of this Agreement. The Milestone Payments for
                  all Knockout Mouse Projects wherein a * * * is requested,
                  shall be determined on a case-by-case basis, upon good faith
                  negotiations between the parties and shall be mutually agreed
                  to in writing by the parties.

3.3      Deltagen shall inform Merck, in writing, of its completion of each
         Milestone, as defined in Appendix A. In such written notice, Deltagen
         shall certify that the Knockout Mice delivered to Merck conform to the
         Knockout Mice specifications for each Knockout Mouse Project set forth
         in Appendix A, and Deltagen shall provide with each delivery of
         Knockout Mice to Merck all of the information and data described in
         Appendix A for each Knockout Mouse Project.

3.4      Subject to payment credit as provided in Section 3.1, Merck shall pay
         all Milestones to Deltagen within thirty (30) days after Merck's
         receipt of written representation from Deltagen of Deltagen's
         completion of Milestones in compliance with the terms of this
         Agreement.

4.       ON-SITE CONSULTATION

4.1      Merck may reasonably request on-site consultations by Deltagen
         personnel relating directly to projects under this Agreement. Merck
         will reimburse Deltagen for all reasonable and reasonably documented
         travel expenses associated with such onsite consultations by Deltagen
         personnel.

4.2      Upon reasonable notice to Deltagen and upon reasonable terms and
         conditions agreed upon by Deltagen and Merck, Merck shall be entitled
         to perform site visits to Deltagen facilities involved in the Knockout
         Mouse Projects to inspect the facilities for compliance with generally
         accepted scientific and animal care procedures including, but not
         limited to those set forth in Appendix A and Section 2.7 above.

5.       TERM AND TERMINATION

5.1      The term of this Agreement shall commence on the Effective Date and
         shall remain in effect until the earlier of either (a) termination of
         this Agreement pursuant to the completion by Deltagen of all Milestones
         under this Agreement or (b) two (2) years from the Effective Date;
         provided, however, that all applicable obligations of Deltagen and
         Merck under this Agreement shall remain in force with respect to any
         Knockout Mouse Project requested by Merck and initiated by Deltagen
         which remains ongoing prior to the date set forth in subsection (b) of
         this paragraph.

5.2      Merck may unilaterally terminate a Knockout Mouse Project for any
         reason. Should Merck at any time during the Knockout Mouse Project
         terminate the development and creation or completion of a specific
         Knockout Mouse Project, Merck shall make the next Milestone Payment
         corresponding to that work being conducted by Deltagen to complete such
         Milestone at the time of termination, as if Deltagen had completed the
         Milestone, regardless of whether such Milestone has been reached.

5.3      Deltagen may terminate a Knockout Mouse Project upon Deltagen's
         identification of technical difficulty beyond the reasonable control of
         Deltagen which would prevent Deltagen from completing the Project using
         commercially reasonable efforts, provided that Deltagen has

* * * Confidential material redacted and separately filed with the Commission.

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         informed Merck, in writing, of the details of such technical
         difficulty, and the parties have had an opportunity to discuss the
         circumstances to attempt to resolve the technical difficulty in a
         reasonable manner. Merck is not entitled to a refund of any past
         Milestone payments paid if a project is terminated as the result of
         technical difficulty beyond the control of Deltagen.

5.4      If either of the Parties is in breach of any obligation under this
         Agreement, the party complaining of said breach shall give written
         notice to the breaching party to remedy such breach. If the breach is
         not remedied within 60 days following the receipt of such notice, the
         party complaining of breach may terminate this Agreement upon written
         notice to the other party at any time and with immediate effect. Any
         such termination will be without prejudice to any other rights which
         the party complaining of breach may have as a result of any breach of
         this Agreement.

6.       CONFIDENTIALITY

6.1      Each party shall treat all information which has been received from the
         other party as strictly confidential ("Information"), and shall not to
         make such Information available to any third party without the express
         prior written consent of the other party and only to use such
         Information for the purposes expressly provided in this Agreement. For
         this purpose, employees and consultants of the parties shall be bound
         by obligations of confidentiality and secrecy no less strict than those
         set out herein and shall not be regarded as third parties.

6.2      The above obligations shall not apply or cease to apply to Information
         which the recipient can show:

         (a)      has become generally available to the public other than
                  through violation of this undertaking;

         (b)      was already in the recipient's rightful possession prior to
                  its acquisition from the disclosing party;

         (c)      was developed independently of information received from the
                  disclosing party;

         (d)      has been lawfully received from a third party, under no
                  obligation to maintain the Information as confidential; or

         (e)      is required to be disclosed by law or court order, provided
                  that notice is promptly delivered to the other party in order
                  to provide an opportunity to challenge or limit such
                  disclosure.

         A statutory obligation to disclose confidential information to
         governmental authorities in connection with the Food and Drug
         Administration product registration procedures is not subject to this
         secrecy obligation.

6.3      This obligation of confidentiality shall survive the expiration and/or
         termination of this Agreement for a period of * * * years.

6.4      Upon expiration or termination of this Agreement, or at any time upon
         the disclosing party's written request, the receiving party shall
         destroy, or at the written request of the disclosing party, deliver to
         the disclosing party any and all Information (including copies)
         received or

* * * Confidential material redacted and separately filed with the Commission.

                                         5

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         generated hereunder, except that the receiving party may,
         for archival purposes, maintain one copy of the Information in its
         confidential legal files.

7.       OWNERSHIP OF RIGHTS

7.1      Deltagen shall own all Deltagen patents and Deltagen technology.
         Additionally, any Deltagen patents or Deltagen technology arising out
         of the work performed pursuant to this Technology Agreement and which
         apply to the production of Knockout Mice shall be owned solely by
         Deltagen. Deltagen hereby grants to Merck a nonexclusive, * * * license
         to Deltagen Patents, Deltagen Technology and Deltagen inventions solely
         arising during the Knockout Mice Projects under this Agreement which
         are useful or necessary for Merck (a) to use, breed and perform further
         research and development using the Knockout Mice generated hereunder
         (and their progeny), and (b) to sublicense such rights to use, breed
         and perform further research and development using the Knockout Mice to
         agents, consultants and Affiliates of Merck; PROVIDED HOWEVER that
         Merck and its sublicencees shall not have a license to use (and shall
         not use) the Knockout Mice (or their progeny), Deltagen Patents,
         Deltagen Technology or Deltagen inventions, directly or indirectly to
         reverse-engineer the methods, processes, techniques or similar Deltagen
         know-how relating directly or indirectly to the design, creation,
         development, generation or production of such "Knockout Mice" or other
         transgenic mice or animals.

7.2      Merck will own all Merck patents and Merck technology. Merck will grant
         to Deltagen a non-exclusive, non-sublicensable license to all Merck
         patents necessary for Deltagen to make Knockout Mice solely for Merck
         according to this Agreement. Merck shall own all phenotypic data and
         characteristics of the Knockout Mice generated by Deltagen for Merck
         under this Agreement; provided however, that Deltagen shall have a
         nonexclusive, nontransferable license to use such phenotypic data and
         characteristics for Deltagen's research analysis solely for Merck in
         accordance with the purposes of this Agreement.

7.3      Joint Patents and Joint Technology will be owned by both Parties
         jointly. Both parties shall decide whether it is desirable for patent
         applications to be filed for Joint Technology developed. If a patent
         application is filed, the Parties shall share costs equally. If one
         party wishes to patent Joint Technology, but the other party does not,
         then the party wishing to file the application may do so at its own
         expense. In such instance, the party filing the application will own
         all rights in the patent application and the other party shall assign
         its rights in the patent application to the party filing the
         application, provided that the non-filing party shall be granted a
         nonexclusive license to use such rights under such patent application.

7.4      Both Parties shall decide whether to maintain patents or patent
         applications within the Joint Patents and the extent of foreign filing
         of such patent applications. If one party wishes to abandon a patent or
         patent application within the Joint Patents, but the other party wishes
         to maintain it, the party wishing to maintain it may do so by paying
         all necessary fees; the party paying the fees shall own all rights in
         this patent or patent application and the other party will assign its
         rights in such patent or patent application to the paying party. If the
         Parties disagree on whether to file a patent application within the
         Joint Patents in any given country, the party wishing to file in such
         country may do so at its own expense, and will own all rights in such
         patent application in such country and the other party will assign its
         rights in such patent application to the party filing the application.

7.5      As of the date of this Agreement, Deltagen represents and warrants to
         Merck that to Deltagen's * * *, Deltagen has the right to enter into
         this Agreement and to grant to Merck the licenses

* * * Confidential material redacted and separately filed with the Commission.

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         hereunder. As of the date of this Agreement, Merck represents and
         warrants to Deltagen that to Merck's * * *, Merck has the right to
         enter into this Agreement and to grant Deltagen the licenses hereunder.

                  Deltagen shall indemnify and hold harmless Merck and its
         Affiliates, Directors, officers,, employees and agents from and against
         any and all losses, Liabilities, damages and expenses (Including
         reasonable attorneys' fees and costs) (collectively "liabilities") that
         they may suffer as a result of any claims, demands, actions or other
         proceedings made or instituted by any third party and arising out of or
         relating to (a) a breach of any representation, warranty or covenant of
         Deltagen under this Agreement or (b) Deltagen's gross negligence or
         willful misconduct, except in each case to the extent such Liabilities
         resulted from the gross negligence or willful misconduct of Merck.

                  Merck shall indemnify and hold harmless Deltagen and its
         directors, officer, employees and agents from and against any and all
         Liabilities that they may suffer as a result of any claims, demands,
         actions or other proceedings made or instituted by any third party and
         arising out of or relating to (a) a breach of any representation,
         warranty or covenant of Merck under this Agreement or (b) Merck's gross
         negligence or willful misconduct except in each case to the extent such
         Liabilities resulted from the gross negligence or willful misconduct of
         Deltagen.

7.6      After Merck has made all applicable Milestone Payments or other
         payments under Section 3.2 above, and upon delivery by Deltagen to
         Merck's designated carrier (FOB), title shall transfer to Merck and
         Merck shall own exclusively all Knockout Mice produced under this
         Agreement, * * * made by Deltagen on behalf of Merck, regardless of
         whether they are * * * or to non-Knockout Mice. Merck shall have the
         exclusive right to use the Knockout Mice, and their progeny, for any
         purpose, without restriction, including, but not limited to, research,
         development, production, breeding, sales and distribution of the
         Knockout Mice to agents, consultants and Merck Affiliates; provided
         however that Merck shall not use the Knockout Mice directly or
         indirectly to reverse-engineer the methods, processes, techniques or
         similar Deltagen know-how relating directly or indirectly to the
         design, creation, development, generation or production of such
         Knockout Mice.

8.       MISCELLANEOUS

8.1      PUBLICATION. If Merck publishes any information, data or material
         regarding the Knockout Mice contemplated under this Agreement, Merck
         shall acknowledge within the publication, the contribution of Deltagen
         to the generation of such mouse or mice.

8.2      FORCE MAJEURE. Neither party shall be liable for its failure to perform
         its obligations under this Agreement due to contingencies beyond its
         reasonable control, including but not limited to strikes, riots, wars,
         fire, flood, accident, labor disputes, embargoes, inability to obtain
         export or import license, acts of God, or acts in compliance with any
         governmental or state law, regulation or other.

8.3      AMENDMENTS. Amendments or modifications of this Agreement may only be
         made by a written Agreement executed by both Parties.

* * * Confidential material redacted and separately filed with the Commission.

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8.4      NOTICES. All notices required or permitted hereunder shall be given in
         writing and sent postage prepaid by first class certified or registered
         mail, or sent by a nationally recognized express courier service, or
         hand delivered at the following addresses:

                           If to Deltagen:
                           William Matthews
                           President
                           Deltagen, Inc.
                           * * *
                           Fax: (650) 610-6823

                           If to Merck:
                           * * *
                           Executive Director
                           Scientific Liaison
                           External Scientific Affairs
                           Merck & Co., Inc.
                           770 Sumneytown Pike
                           P.O. Box 4, WP42-217
                           West Point, PA 19486

8.5      REPRESENTATIONS AND WARRANTIES.  Each party represents and warrants
         that:

         8.5.1    It will use commercially reasonable efforts to complete its
                  obligations under this Agreement in compliance with any and
                  all applicable federal, state, or local laws, regulations and
                  guidelines.

         8.5.2    It shall devote the necessary level of personnel and resources
                  to conduct and complete its obligations in a commercially
                  reasonable manner under this Agreement.

8.6      LIMITATION OF WARRANTY AND LIABILITY. EXCEPT AS OTHERWISE EXPRESSLY SET
         FORTH IN THIS AGREEMENT, DELTAGEN MAKES NO WARRANTIES, EXPRESS OR
         IMPLIED, WITH RESPECT TO THE KNOCKOUT MICE GENERATED UNDER THIS
         AGREEMENT OR THE KNOCKOUT MOUSE PROJECTS. DELTAGEN DISCLAIMS ALL OTHER
         WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION A WARRANTY
         OF NON-INFRINGEMENT AND THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
         FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL EITHER PARTY BE
         LIABLE FOR LOSS OF PROFITS OR INCIDENTAL, SPECIAL OR CONSEQUENTIAL
         DAMAGES DIRECTLY OR INDIRECTLY ARISING OUT OF THIS AGREEMENT OR THE
         RESEARCH, DEVELOPMENT, GENERATION OR USE OF THE KNOCKOUT MICE UNDER
         THIS AGREEMENT.

8.7      APPLICABLE LAW AND VENUE. This Agreement shall be governed by and
         construed in accordance with the laws of the State of California as
         though made and performed in said state without regard to its conflict
         of law revisions.

8.8      COUNTERPARTS. This Agreement may be executed in counterparts, each of
         which shall be deemed an original, but all of which together shall
         constitute one and the same instrument.

* * * Confidential material redacted and separately filed with the Commission.

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8.9      U.S. EXPORT LAWS AND REGULATIONS. Without limitation, each party shall
         comply with all laws and regulations of the United States relating to
         the export of biological materials, products and technical information.

8.10     ENTIRE AGREEMENT. This Agreement contains the entire understanding of
         the parties with respect to the subject matter hereof. All express or
         implied Agreements -and understandings, either oral or written,
         heretofore made are expressly superseded by this Agreement.

8.11     INDEPENDENT CONTRACTORS. It is expressly agreed that Deltagen and Merck
         shall be independent contractors and that the relationship between the
         two parties shall not constitute a partnership, joint venture or
         agency. Neither Deltagen nor Merck shall have the authority to make any
         statements, representations or commitments or any kind, or to take any
         action, which shall be binding on the other, without the prior consent
         of the party to do so.

8.12     WAIVER. The waiver by either party of any right hereunder or the
         failure to perform or of a breach by the other party shall not be
         deemed a waiver of any other right hereunder or of any other breach or
         failure by said other party whether of a similar nature or otherwise.

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AGREED AND ACCEPTED:

DELTAGEN, INC.                           MERCK & CO., INC.

BY  /s/ William Matthews                 BY   /s/ C. Thomas Caskey
   ----------------------------              -----------------------------

NAME  William Matthews                   NAME  C. Thomas Caskey

TITLE  President                         TITLE  Senior Vice President, Research

DATE  July 13th, 1998                    DATE  July 10, 1998

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                                   APPENDIX A

        [Superceded by Appendix A to Amendment to Technology Agreement]

                                       11

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                                   APPENDIX B

   FORM NOTIFICATION LETTER FOR INITIATION OF A NEW KNOCKOUT-MOUSE PROJECT

                               (Template follows)
                               (Merck letterhead)

Date

Bill Matthews, Ph.D.
President
Deltagen, Inc.
***

Dear Bill,

This letter is to provide notice to Deltagen of Merck's request to Deltagen to
initiate work on a Knockout Mouse Project under the terms and conditions of the
Technology Agreement between Deltagen, Inc. and Merck, dated
_____________________ (the "Agreement"), including, but not limited to, the
confidentiality obligations of the Agreement. The Knockout Mouse Project to be
initiated is described as follows:

The Merck contact scientist for technical information regarding the project will
be:

Merck requests that Deltagen begin to work to develop the above described
Knockout Mouse on the terms and conditions of the above-referenced Agreement.

Sincerely,

Merck's Signatory

Agreed,

-------------------------------------
Deltagen

* * *  Confidential material redacted and separately filed with the Commission.

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                                  AMENDMENT TO
                              TECHNOLOGY AGREEMENT

         THIS AMENDMENT TO TECHNOLOGY AGREEMENT, dated as of December 21, 1999
(this "Amendment"), is entered into between DELTAGEN, INC. ("Deltagen"), having
a place of business at 1003 Hamilton Avenue, Menlo Park, California 94025, and
MERCK & CO, INC. ("Merck"), having a place of business at One Merck Drive, P.O.
Box 100, Whitehouse Station, New Jersey 08889-0100, and is made with reference
to the following facts:

         A. WHEREAS, the parties entered into that certain Technology Agreement
on July 13, 1998 (the "Technology Agreement").

         B. WHEREAS, the parties desire to modify the Technology Agreement to
increase the number of Knockout Mice under the Technology Agreement, to extend
the term of the Technology Agreement and to modify such other terms as set forth
below.

         NOW, THEREFORE, in consideration of the mutual covenants set forth
below and other valuable consideration, the receipt and sufficiency of which is
hereby acknowledged, the parties hereby amend the License Agreement, and agree
as follows:

1.       AMENDMENTS.

1.1      The first sentence of Section 2.3 is hereby restated in its entirety
         as follows:

                    Deltagen shall undertake * * * Knockout Mice Projects
                    according to the terms and conditions set forth in this
                    Agreement.

1.2      AMENDMENT TO SECTION 3.1.  Section 3.1 is hereby restated in its
         entirety to read as follows:

                    Merck shall pay to Deltagen * * * of the total estimated
                    cost for the * * * Knockout Mouse Projects and the * * *
                    Knockout Mouse Projects as set forth in Appendix A. Such
                    payment shall be nonrefundable and shall be credited against
                    the Milestones as set forth in Appendix A.

1.3      AMENDMENT TO SECTION 5.1.  Section 5.1 is hereby restated in its
         entirety to read as follows:

                   The term of this Agreement shall commence on the Effective
                   Date and shall remain in effect until the earlier of either
                   (a) termination of this Agreement pursuant to the completion
                   by Deltagen of all Milestones under this Agreement as amended
                   or (b) December 31, 2002; provided however, that all
                   applicable obligations of Deltagen and Merck under this
                   Agreement shall remain in force with respect to any Knockout
                   Mouse Project requested by Merck and initiated by Deltagen
                   which remains ongoing prior to the date set forth in
                   subsection (b) of this paragraph.

* * *  Confidential material redacted and separately filed with the Commission.

                                       13
<PAGE>

1.4      AMENDMENT TO SECTION 8.4. The second paragraph of Section 8.4,
         beginning with the phrase "If to Deltagen" and ending with "6823" is
         hereby modified as follows:

                   If to Deltagen:

                   * * *

         President
         Deltagen, Inc.
         1003 Hamilton Avenue
         Menlo Park, CA.
         94025

1.5      AMENDMENT TO APPENDIX A. Appendix A is hereby restated in its
         entirety as set forth in Appendix A attached hereto.

2.       INITIATION PAYMENT. IN PARTIAL CONSIDERATION FOR THIS AMENDMENT, WITHIN
         THIRTY (30) DAYS AFTER THE DATE OF THIS AMENDMENT, MERCK SHALL PAY TO
         DELTAGEN THE SECOND INITIATION PAYMENT OF $300,000.00 SET FORTH IN
         APPENDIX A OF THIS AGREEMENT AS AMENDED.

3.       CONTINUING EFFECT. THIS AMENDMENT SHALL BE EFFECTIVE FOR ALL PURPOSES
         AS OF THE DATE FIRST SET FORTH ABOVE. EXCEPT AS OTHERWISE EXPRESSLY
         MODIFIED BY THIS AMENDMENT, THE TECHNOLOGY AGREEMENT SHALL REMAIN IN
         FULL FORCE AND EFFECT IN ACCORDANCE WITH ITS TERMS.

4.       DEFINED TERMS. ALL TERMS USED, BUT NOT DEFINED, IN THIS AMENDMENT SHALL
         HAVE THE RESPECTIVE MEANINGS AS SET FORTH IN THE TECHNOLOGY AGREEMENT.

[Intentionally Left Blank]

* * *  Confidential material redacted and separately filed with the Commission.

                                       14

<PAGE>

5.       COUNTERPARTS.  THIS AMENDMENT MAY BE EXECUTED IN COUNTERPARTS, EACH OF
         WHICH SHALL BE DEEMED AN ORIGINAL, BUT ALL OF WHICH TOGETHER SHALL
         CONSTITUTE ONE AND THE SAME INSTRUMENT.

         IN WITNESS WHEREOF, the parties have executed this Amendment as of the
date first set forth above.

                                     DELTAGEN, INC.

                                     By:   /s/ Augustine Yee
                                           ----------------------------------

                                     Its:  Vice President Corporate Development
                                           ----------------------------------

                                     MERCK & CO, INC.

                                     By:   /s/ Anthony Ford-Hutchinson
                                           ----------------------------------
                                               Anthony Ford-Hutchinson

                                     Its:  Senior Vice President
                                           ----------------------------------
                                           Basic Research
                                           ----------------------------------

* * *  Confidential material redacted and separately filed with the Commission.

                                       15

<PAGE>

                             APPENDIX A TO AMENDMENT

                                   APPENDIX A

I.       SCIENTIFIC MILESTONES AND PAYMENT SCHEDULE FOR THE FIRST * * * KNOCKOUT
         MOUSE PROJECTS UNDER THIS TECHNOLOGY AGREEMENT

         The following payments and milestones are with respect to the first
* * * Knockout Mouse Projects undertaken by Deltagen pursuant to the
Technology Agreement. Within * * * of the Effective Date, Deltagen is to
begin development and generation of up to * * * Knockout Mice Projects and
Merck shall pay Deltagen 30% ($255,000) of the * * * of * * * Knockout Mice
Projects (the first * * * gene knockouts are * * *).

         Subsequent payments to Deltagen will be based on the achievement of the
specific Milestones for each knockout as outlined below. Merck understands and
acknowledges that production of Knockout Mouse Project involves a number of
technologically complex steps, and that the time periods for performance are
reasonable estimates only and subject to change due to technological
difficulties encountered. Deltagen shall be obligated to notify Merck of any
such technical difficulties as soon as reasonably possible after they arise, and
the parties will commence good faith discussions to resolve such technical
difficulties in a reasonable manner.

Payment by Merck for initiation of contract:

                                                                        $255,000

The following payments are per Knockout Mouse Project for the first * * *
Projects:

Milestone 1 - * * *                                          $ * * *

Milestone 2 - * * *                                          $ * * *

Milestone 3 - * * *                                          $ * * *

Milestone 4 - * * *                                          $ * * *

Milestone 5 - * * *                                          $ * * *

MILESTONE 1:              * * *
                          Deltagen will * * * based * * *. The cost for * * * is
                          included in the deposit paid by Merck. Anticipated
                          time frame for completion will be within * * * after
                          receipt of necessary * * * information. In the event
                          of unforeseen

* * *  Confidential material redacted and separately filed with the Commission.

                                       16

<PAGE>

                          technical difficulties in * * * resulting from
                          * * *, Deltagen (upon consultation with
                          Merck) will * * *. The reasonable cost for this
                          * * * will be determined on a case-by-case basis,
                          after good faith negotiations between the
                          parties * * *.

MILESTONE 2:              * * *
                          Deltagen will * * *. Deltagen will * * * a maximum
                          of * * *. Deltagen will receive * * * upon the
                          identification of a * * * or Deltagen's * * * of
                          * * *. If * * * in the * * * clones, Deltagen will
                          first * * * or alternatively, * * * (after
                          consultation with, and written agreement by, Merck).
                          The cost of a * * * will not exceed * * *. Cost for
                          * * * will be * * * per * * * colonies * * *.
                          Anticipated time for completion of * * * will be
                          * * * from receipt of * * *. Confirmation of * * *
                          will be obtained * * *. Merck will also receive
                          * * * information in order to confirm * * *.

MILESTONE 3:              * * *
                          Deltagen will transfer up to * * *. Upon the * * *
                          from each * * *, Deltagen will receive a payment of
                          * * * per * * *. Anticipated time frame for
                          completion will be within * * * from receipt of
                          * * *. Deltagen will confirm the * * *.

MILESTONE 4:              * * *
                          Deltagen will * * * animals for * * *. For production
                          of ** * mice with the desired * * *, Deltagen will
                          receive * * * per * * *. Anticipated time frame will
                          be within * * * from receipt of the * * *. The * * *
                          of the * * * will be confirmed * * *.

MILESTONE 5:              * * *
                          Deltagen will perform the following analysis on up to
                          * * * gene Knockout Mice that are generated * * *.
                          * * * mice will * * *. * * * mice will be * * *
                          animals. In cases where the gene knockout produces
                          a * * *, Deltagen will make reasonable efforts to
                          determine * * *. Each * * * will be inspected for
                          * * *. * * * will be monitored * * *. At * * * mice
                          from * * * from each knockout line will be * * * with
                          that will include the following * * *. * * * will be
                          * * * and Deltagen will prepare a written report of
                          all findings. Deltagen will also * * * to Merck upon
                          request. In addition to the above analysis, Deltagen
                          will provide * * *. * * * will * * *. * * * will also
                          be * * *.

                          Upon completion of * * * Knockout Mouse Project,
                          Deltagen will receive * * * per * * *. Anticipated
                          time frame is within * * * from receipt of * * *.

                          All mice in the Deltagen animal facility will be
                          tested routinely for * * *. Results will be provided
                          to Merck on a * * * basis.

II.      Scientific Milestones and Payment Schedule for the Second * * *
         Knockout Mouse Project under this Technology Agreement

* * *  Confidential material redacted and separately filed with the Commission.

                                       17

<PAGE>

         The following payments and milestones are with respect to the Second
* * * Knockout Mouse Projects undertaken by Deltagen pursuant to the
Technology Agreement. In partial consideration for Deltagen's agreement to
undertake the Second * * * Knockout Mouse Projects under the Technology
Agreement, within * * * of the date of this Amendment Merck shall pay to
Deltgen an initiation payment (the "Second Initiation Payment") of 30%
($300,000) of the total aggregate amount of such Second * * * Knockout Mice
Projects (the second * * *gene knockouts are * * *).

         Subsequent payments to Deltagen will be based on the achievement of the
specific Milestones for each knockout as outlined below. Merck understands and
acknowledges that production of each Knockout Mouse Project involves a number of
technologically complex steps, and that the time periods for performance are
reasonable estimates only and subject to change due to technological
difficulties as soon as reasonably possible after they arise, and the parties
will commence good faith discussions to resolve such technical difficulties in a
reasonable manner.

Second Initiation payment by Merck:  $300,000

The following payments are per Knockout Mouse Project for the Second * * *
Projects:

Milestone 1 - * * *                                          $ * * *

Milestone 2 - * * *                                          $ * * *

Milestone 3 - * * *                                          $ * * *

Milestone 4 - * * *                                          $ * * *

Milestone 5 - * * *                                          $ * * *

MILESTONE 1:              * * * Deltagen will * * * based on * * *. The cost
                          for * * * is included in the deposit paid by Merck.
                          Anticipated time frame for completion will be
                          within * * * after receipt of necessary * * *
                          information. In the event of unforeseen technical
                          difficulties in * * * resulting from * * *,
                          Deltagen (upon consultation with Merck) will * * *.
                          The reasonable cost for this * * * will be
                          determined on a case-by-case basis, after good
                          faith negotiations between the parties * * *.

MILESTONE 2:              * * *
                          Deltagen will * * *. Deltagen will * * * a maximum of
                          * * *. Deltagen will

* * *  Confidential material redacted and separately filed with the Commission.

                                       18

<PAGE>

                          receive * * *upon the identification of a * * * or
                          Deltagen's * * *. If * * * in the first * * *,
                          Deltagen will first * * * or alternatively, * * *
                          (after consultation with, and written agreement by,
                          Merck). The cost of a * * * will not exceed * * *.
                          Cost for * * *will be * * *per  * * *. Anticipated
                          time for completion of * * *will be * * *from receipt
                          of * * *. Confirmation of * * * will be obtained
                          * * *. Merck will also receive * * * in order to
                          confirm * * *.

MILESTONE 3:              * * *
                          Deltagen will transfer up to * * *. Upon the * * *
                          from each * * *, Deltagen will receive a payment of
                          * * * per * * *. Anticipated time frame for completion
                          will be within * * * from receipt of * * *. Deltagen
                          will confirm the * * *.

MILESTONE 4:              * * *
                          Deltagen will * * * animals for * * *. For production
                          of * * * mice with the desired * * *, Deltagen will
                          receive * * * per * * *. Anticipated time frame will
                          be within * * * from receipt of the * * *. The * * *
                          of the * * * will be confirmed * * *.

MILESTONE 5:              * * *
                          Deltagen will perform the following analysis on up to
                          * * * gene Knockout Mice that are generated * * *will
                          be * * * mice will be * * * animals. In cases where
                          the gene knockout produces a * * *, Deltagen will make
                          reasonable efforts to determine * * *. Each * * * will
                          be inspected for * * * will be monitored * * *. At
                          * * * mice * * * from each knockout line will be * * *
                          with that will include the following * * * will be * *
                          * and Deltagen will prepare a written report of all
                          findings. Deltagen will also * * * to Merck upon
                          request. In addition to the above analysis, Deltagen
                          will provide * * * will include * * * will also be
                          * * *.

                          Upon completion of * * * Knockout * * * per
                          Knockout Mouse Project. Anticipated time frame is
                          within * * * from receipt of * * *.

                          All mice in the Deltagen animal facility will be
                          tested routinely for * * *. Results will be provided
                          to Merck on a * * * basis.

* * *  Confidential material redacted and separately filed with the Commission.

                                       19<PAGE>

                                                                   Exhibit 10.21

       PORTIONS OF THIS EXHIBIT HAVE BEEN OMITTED BASED ON A REQUEST FOR
                             CONFIDENTIAL TREATMENT

                DELTASELECT-TM- COLLABORATIVE SERVICES AGREEMENT

         This DeltaSelect-TM- Collaborative Services Agreement, including all
attachments hereto, (this "Agreement") is entered into as of June 27, 2000 (the
"Agreement Date"), by and between DELTAGEN, INC., a Delaware corporation having
a place of business at 1003 Hamilton Avenue, California 94025 ("DELTAGEN"),
GLAXO GROUP LIMITED ("GGL") AND GLAXO RESEARCH AND DEVELOPMENT LIMITED ("GWRD"),
each incorporated in England with a place of business at Glaxo Wellcome House,
Berkeley Avenue, Greenford, Middlesex UB6 ONN, United Kingdom (GGL and GWRD
together with their Affiliates being collectively, "GLAXO").

         WHEREAS, DELTAGEN possesses certain knowledge and experience in the
research, creation, design and generation of Standard Knockout Mice and to
establish a pilot program to create, design and generate Conditional Knockout
Mice and Knock-In Mice; and

         WHEREAS, GLAXO desires to engage DELTAGEN to generate for GLAXO, in
accordance with this Agreement, Standard Knockout Mice and, assuming the pilot
program is successful, Conditional Knockout Mice and Knock-In Mice, and DELTAGEN
desires to undertake such engagement as set forth herein.

         NOW THEREFORE, in consideration of the mutual covenants set forth
below, DELTAGEN and GLAXO (individually "Party" and collectively "Parties")
agree as follows:

1.       DEFINITIONS.

         1.1      "Affiliate" shall mean, with respect to a party to this
Agreement, any entity directly or indirectly controlling or controlled by or in
common control with such party, where "control" is defined as the ownership of
at least *** of the equity or beneficial interests of such entity, or the right
to vote for or appoint a majority of the board of directors or other governing
body of such entity.

         1.2      "Budget" means the pricing and payment terms for a Standard
Knockout Mice Project, Conditional Knockout Mice Project or Knock-In Mice
Project, each as set forth in Attachment I attached hereto.

         1.3      "Conditional Knockout Mouse" or "Conditional Knockout Mice"
means, a mouse or mice generated or provided pursuant to this Agreement in which
***.

         1.4      "Conditional Knockout Mice Project" means a specific project
to create and generate particular Conditional Knockout Mice in accordance with
the terms of a specific Scope of Work under this Agreement.

         1.5      "Confidential Information" means the content of this
Agreement, the DELTAGEN Technology, the Data, the GLAXO Technology, the Study
Materials, and, with respect to a party, all data and/or information of any kind
whatsoever (including without limitation, data, databases, compilations,
formulae, schemata, models, patent disclosures, procedures, processes,
projections, protocols, results of experimentation and testing,

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       1
<PAGE>

specifications, strategies and techniques), and all tangible and intangible
embodiments thereof of any kind whatsoever (including without limitation,
apparatus, compositions, documents, drawings, machinery, patent applications,
records, laboratory and research notebooks, memoranda and reports), which are
disclosed by such party to the other party and is marked, identified as or
otherwise acknowledged to be confidential at the time of disclosure to the other
party.

         1.6      "*** Mouse" or "*** Mice" means a mouse or mice that have
been engineered, ***.

         1.7      "Data" means all data or information generated under a Project
under this Agreement, including but not limited to all information, records,
reports and other material(s) required to be generated, collected or analyzed by
DELTAGEN thereunder.

         1.8      "DELTAGEN Technology" means all Inventions owned by or ***
DELTAGEN related to ***.

         1.9      "Effective Commencement Date" means the commencement date for
a particular Project, either as specified in this Agreement or, if different, as
specified in the applicable Scope of Work.

         1.10     "*** Mouse" or "*** Mice" means a mouse or mice that
contain one or more regions of DNA that have been engineered ***.

         1.11     "GLAXO Representative" means the representative identified in
writing by GLAXO to DELTAGEN on a Scope of Work, as such representative may be
changed from time to time in writing by GLAXO.

         1.12     "GLAXO Technology" means all Inventions and *** owned by or
licensed to GLAXO ***.

         1.13     "Inventions" means technology, information, data, know-how,
inventions, improvements and all patent, copyright, trade secret, and other
intellectual property rights therein and thereto.

         1.14     "Knock-In Mice" means, ***; mice or a mouse generated pursuant
to this Agreement that have ***.

         1.15     "Knock-In Mice Project" means a specific project to create and
generate Knock-In Mice in accordance with the terms of a specific Scope of Work
under this Agreement.

         1.16     "Milestone" means the milestones set forth on the Scope of
Work attached hereto.

         1.17     "Project" means a Standard Knockout Mice Project, Conditional
Knockout Mice Project or Knock-In Mice Project, as the context requires.

         1.18     "Project Mice" means, with respect to a particular Project,
the specific mouse or mice that are generated in the performance of such Project
(i.e., the particular animals

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       2
<PAGE>

themselves); Project Mice may be Standard Knockout Mice, Conditional Knockout
Mice or Knock-In Mice, depending on the Project.

         1.19     "Scope of Work" means the mutually agreed, applicable written
work plan for a Project, substantially in the form attached hereto as
Attachment I and more particularly as Section IA of Attachment I (Standard
Knockout Mice Project), Section IB of Attachment I (Conditional Knockout Mice
Project) and Section IC of Attachment I (Knock-In Mice Project).

         1.20     "Standard Knockout Mouse" or "Standard Knockout Mice" ***,
mice or a mouse generated pursuant to this Agreement that have ***.

         1.21     "Standard Knockout Mice Project" means a specific project to
create and generate Standard Knockout Mice in accordance with the terms of a
specific Scope of Work under this Agreement.

         1.22     "Standard Mutation" means the interruption, disruption or
deletion in a portion of a specified gene.

         1.23     "Study Materials" means any samples or materials (including
chemical or biological) provided by GLAXO to DELTAGEN for purposes of a Project
under this Agreement.

2.       PROJECTS

         2.1      INDIVIDUAL PROJECTS. If GLAXO wishes to have DELTAGEN perform
a Project under this Agreement, GLAXO shall initiate each such request for a
Scope of Work by notifying DELTAGEN in writing in the form set forth in
Attachment II and providing a description of the particular Project requested as
well as the information set forth in Section 2.2 and the Scope of Work. DELTAGEN
shall evaluate each such request to determine whether such Project is feasible,
if DELTAGEN requires technical or scientific modifications or if DELTAGEN
requires additional information to undertake such evaluation. If such Project in
DELTAGEN's reasonable discretion is commercially or technically infeasible,
DELTAGEN shall have the right (without penalty) to decline to undertake such
Project. The terms of this Agreement, together with the applicable Scope of Work
and the Budget, shall form the entire agreement of the Parties with respect to
each particular Project.

         2.2      INITIATION OF PROJECTS. Prior to DELTAGEN's initiation of each
Project, GLAXO shall:

                  2.2.1    Identify to DELTAGEN in writing each Project to be
initiated and agree in writing with DELTAGEN upon the Scope of Work for such
Project;

                  2.2.2    GLAXO shall be solely responsible for providing to
DELTAGEN the data and information *** and other information for such Project.

                  2.2.3    Consult with and agree in writing with DELTAGEN
regarding any proposed modifications or additions to the form of Scope of Work
attached as Attachment I for such Project.

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       3
<PAGE>

                  2.2.4    Provide in writing to DELTAGEN *** and other
information, materials and data reasonably required by DELTAGEN to undertake
such Project (including the Starting Materials specified in Attachment I).

                  2.2.5    Transfer to DELTAGEN, to the extent possible and
under appropriate license if applicable, *** and other GLAXO Technology
licensed, owned by or otherwise available to GLAXO for use solely by DELTAGEN
and its subcontractors (see Section 10) and solely on the Project, that may be
suitable* * *.

         2.3      COMMENCEMENT OF PROJECT WORK. Unless otherwise specified in
its Scope of Work, each Project conducted hereunder shall commence *** after
written agreement by both parties on a Scope of Work and DELTAGEN's receipt from
GLAXO of all information and materials set forth in Section 2.2 above relating
to such Project .

         2.4      PERFORMANCE. DELTAGEN shall use commercially reasonable
efforts to perform its obligations under this Agreement, PROVIDED THAT, GLAXO
acknowledges and agrees that the performance of the Projects involves a number
of technologically complex steps and that any time periods for performance and
the Scope of Work may be subject to change due to potential technological
difficulties encountered. DELTAGEN shall notify GLAXO of technical difficulties
as soon as reasonably practicable after such difficulties are encountered and
the parties shall discuss and agree in good faith upon methods to resolve such
technical difficulties in a reasonable manner.

         2.5      COMPLETION OF PROJECT. Each Project shall be deemed complete
upon GLAXO's receipt of the Data for such Project under Section 9 below *** set
forth in the Scope of Work for such Project, unless GLAXO and DELTAGEN mutually
agree otherwise.

         2.6      ADHERENCE TO SCOPE OF WORK. DELTAGEN shall perform those
activities described in the Scope of Work for each Project. Neither Party shall
change or deviate from a Scope of Work in any material manner or degree without
the prior written consent of the other Party.

         2.7      CHANGES TO A PROJECT. GLAXO shall have the right, from time to
time, to propose modifications to the Scope of Work of a Project. If GLAXO
proposes to change any terms of a Project, including but not limited to the
estimated time schedule for such Project, GLAXO shall submit such
modification(s) in writing to DELTAGEN (the "Proposed Modification"). Such
Proposed Modification shall be implemented by the Parties upon the written
agreement of both parties to such Proposed Modification (which agreement shall
not be unreasonably withheld) and a revised Budget and time schedule for such
Proposed Modification. DELTAGEN shall have the right, in its commercially
reasonable discretion, to accept or reject such Proposed Modification based upon
DELTAGEN's good faith reasonable belief as to whether such proposed
modifications would alter DELTAGEN's technical, performance or financial
obligations under a Scope of Work.

         2.8      STANDARDS OF WORK AND ANIMAL CARE. With respect to each
Project, DELTAGEN shall comply with:- (a) all applicable *** standards and good
industry standards regarding the maintenance and care of the Standard Knockout
Mice, Conditional Knockout Mice or Knock-In Mice involved in a particular
Project; (b) laboratory animal care and welfare as

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       4
<PAGE>

reasonably implemented by Deltagen in its facilities and operations; (c) ***.
Upon the request of GLAXO, DELTAGEN shall promptly provide a written report to
GLAXO concerning DELTAGEN's maintenance and care of the Standard Knockout Mice,
Conditional Knockout Mice or Knock-In Mice involved in a particular Project.

         2.9      CONDITIONAL KNOCKOUT MICE AND KNOCK-IN MICE. Notwithstanding
anything to the contrary contained in this Agreement, GLAXO acknowledges and
agrees that all Projects involving *** are undertaken ***. The Milestones
associated with the implementation of a pilot project to produce Conditional
Knockout Mice or Knock-In Mice will be set forth in the applicable Scope of
Work.

3.       PAYMENTS AND BUDGET.

         3.1      BUDGET. GLAXO shall pay to DELTAGEN the payments set forth in
the Budget for each Project. Except as set forth in a revised Budget under
Section 3.2 below, such payments shall constitute full payment for such Project,
including all labor, materials and overhead and GLAXO shall have no other
payment obligations hereunder.

         3.2      PAYMENTS. DELTAGEN shall submit invoices to GLAXO for the
payments set forth in the Scope of Work and Budget separately for each Project,
upon DELTAGEN's completion of each Milestone set forth in the Scope of Work and
Budget for that Project. GLAXO shall pay all DELTAGEN's invoices at the end of
the month after the month in which such invoice is received. DELTAGEN shall
include with each invoice a written statement of DELTAGEN's completion of all
Milestones for which payment is being sought. Upon request, DELTAGEN will
provide reasonable supporting documentation, to the extent available,
demonstrating or substantiating such completion.

         3.3      MAXIMUM OBLIGATION. In no event shall DELTAGEN be obligated to
provide services or to undertake any Projects that would cause the aggregate
amount payable under this Agreement for all Projects, ***, to exceed ***.

         3.4      PAYMENT WITHOUT DEDUCTION. All payments due under this
Agreement will be made in full without deduction for or on account of any
present or future taxes or duties of whatever nature that may be imposed, except
as provided in Section 3.5.

         3.5      WITHHOLDING TAXES. GLAXO *** from amounts otherwise due
hereunder and as compelled by applicable law and shall remit the amount
withheld to the appropriate taxing authorities on DELTAGEN's behalf and the
remainder to DELTAGEN. GLAXO will provide DELTAGEN with a written receipt or
a tax deduction certificate from the tax authority for all taxes so withheld.
GLAXO will cooperate with DELTAGEN in obtaining exemption from such
withholding and in minimizing or avoiding any such tax withholding
requirement, as available under applicable law.

         3.6      CURRENCY. All amounts due under this Agreement are payable
in US Dollars.

4.       RIGHTS TO INVENTIONS.

         4.1      DELTAGEN'S INVENTIONS. DELTAGEN shall own all DELTAGEN
Technology.

         4.2      GLAXO'S INVENTIONS. GLAXO shall own all GLAXO Technology.

         4.3.1    PROJECT MICE OWNERSHIP. With respect to *** under this
Agreement, after GLAXO has made to DELTAGEN all payments associated with
Milestones that have

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       5
<PAGE>

arisen and been completed by DELTAGEN and all other payments due under this
Agreement for such Project, ***:

                  4.3.1    ***, DELTAGEN shall continue to own all of the
DELTAGEN Technology applicable thereto, inherent therein or embodied thereby.

                  4.3.2    Conditioned on payment in full of all amounts due as
described above, DELTAGEN grants GLAXO a non-exclusive license under the
DELTAGEN Technology to use such Project Mice, ***, for internal research only
and not for any other use or purpose. *** For the avoidance of doubt, nothing
contained in this Section 4.3.2. shall constrain in any way GLAXO's right to
commercialize as it sees fit the results of any of its research on Project Mice
or results derived from its use of DELTAGEN Technology so long as such
commercialization or related activities do not infringe or misappropriate of any
of DELTAGEN's intellectual property or other proprietary rights, do not make or
constitute any unauthorized or unlicensed use of the DELTAGEN Technology, and do
not make unauthorized use or disclosure of any of DELTAGEN's Confidential
Information.

                  4.3.3    Except as expressly set forth in the applicable Scope
of Work, DELTAGEN shall not transfer to a third party any Project Mice (except
***) generated by DELTAGEN for GLAXO under this Agreement.

                  4.3.4    GLAXO acknowledges and agrees that, subject to
Section 4.3.5, (a) DELTAGEN may at any time (past, present or future),
independently or with or for others, research, develop and/or commercialize
the *** provided by GLAXO to DELTAGEN under this Agreement; (b) DELTAGEN may
at any time (past, present or future), independently or with or for others,
research, develop and/or commercialize any other mice that are derived from
DELTAGEN's work for GLAXO under the Project but not the Project Mice, either
for DELTAGEN's own products and programs or for a third party; and (c)
DELTAGEN or a third party may at any time, independently (or with others)
have secured, own or be seeking patent or other intellectual property rights
with respect to, or with respect to the use of any other mice that are
derived from DELTAGEN's work for GLAXO under the Project but not the Project
Mice.

                  4.3.5    Notwithstanding anything to the contrary in this
Agreement, GLAXO shall not use the Project Mice or any Data, results or other
information provided by DELTAGEN to GLAXO to reverse-engineer or practice (and
GLAXO shall not directly or indirectly acquire rights to) any of the DELTAGEN
Technology or any of DELTAGEN's or any of its licensor's methods, processes,
techniques, inventions, know-how or intellectual property rights relating
directly or indirectly to the design, creation, development, generation or
production of Standard Knockout Mice, Conditional Knockout Mice, Knock-In Mice
or transgenic animals.

         4.4      DELTAGEN'S USE OF ***. Except where technically infeasible or
the applicable Scope of Work provides otherwise, DELTAGEN shall perform all
Projects under this Agreement *** and (c) DELTAGEN shall *** other than as
allowed by the applicable Scope of Work or as reasonably required in the
performance of its obligations under the Project or pursuant to this Agreement;
PROVIDED, HOWEVER, that this Section 4.4 shall not limit the use or disclosure
by DELTAGEN of the same or similar information when independently generated or
obtained from

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       6
<PAGE>

other sources or the independent generation by DELTAGEN of the same or similar
mice ***. In addition to any other remedies available to GLAXO at Law, equity
or under this Agreement, any breach of this Section 4.4 by DELTAGEN that is not
willful or intentional shall constitute a basis for termination by GLAXO of this
Agreement but not any other agreement between DELTAGEN and GLAXO, subject to
DELTAGEN's applicable rights of notice and opportunity to cure. Any willful or
intentional breach of this Section 4.4 by Deltagen shall constitute the basis
for termination by Glaxo of this Agreement and of any other Agreement between
Deltagen and Glaxo, subject to DELTAGEN's applicable rights of notice and
opportunity to cure. *** shall be entitled, upon payment to DELTAGEN of all
amounts due hereunder, to continue to use all (i) all *** generated by DELTAGEN
or its subcontractors from those particular animals in the course of performing
such Project, and (ii) all ***, in each case subject to Sections 4.3.1 through
4.3.6.

         4.5      NO OTHER TECHNOLOGY RIGHTS OR LICENSES. No Party shall, as a
result of this Agreement, obtain any ownership interest, license or other right
(whether express or implied, including without limitation licenses or other
rights with respect to any patent or other intellectual property rights owned by
or licensed to the other Party or a third party (whether to Project Mice and/or
*** or otherwise)) in any technology, Confidential Information or other data or
information, know-how, patents, pending patent applications, products, programs,
materials or intellectual property rights of the other Party, including items
owned, controlled or developed by such other Party or transferred by such other
Party pursuant to this Agreement.

5.       CONFIDENTIALITY.

         5.1      CONFIDENTIAL INFORMATION. Except as otherwise expressly
provided in this Agreement, for a period of ten (10) years from the later of the
date of disclosure or the date of termination of this Agreement, (a) each Party
shall maintain in confidence the Confidential Information of the other Party;
(b) neither Party shall use, disclose or grant the use of the other's
Confidential Information, except on a "need-to-know" basis to those directors,
officers, employees, and agents to the extent such disclosure is reasonably
necessary in connection with its activities as expressly authorized by this
Agreement and (c) to the extent that disclosure is authorized by this Agreement,
prior to such disclosure, the Party wishing to disclose the other Party's
Confidential Information shall obtain the written agreement of any such person
who is not otherwise bound by confidentiality obligations at least as
restrictive as the obligations set forth in this Agreement, to hold in
confidence and not make use of the Confidential Information for any purpose
other than those permitted by this Agreement.

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       7
<PAGE>

         5.2      PERMITTED DISCLOSURES. The nonuse and nondisclosure
obligations contained in this Article 5 shall not apply to data and/or
information which the other party can establish by written documentation (a) to
have been publicly known prior to disclosure of such data and/or information by
the disclosing party to the other party, (b) to have become publicly known,
without fault on the part of the other party, subsequent to disclosure of such
data and/or information by the disclosing party to the other party, (c) to have
been received by the other party at any time from a source, other than the
disclosing party, rightfully having possession of and a right to disclose such
data and/or information, (d) to have been otherwise known by the other party
prior to disclosure of such data and/or information by the disclosing party to
the other party, or (e) to have been independently developed by the employees or
agents of the other party without access to or the use of such data and/or
information disclosed by the disclosing party to the other party.

         5.3      TERMS OF THIS AGREEMENT. Neither Party shall disclose any
terms or conditions of this Agreement (including without limitation the Budget)
to any third party without the prior consent of the other Party, except as
required by applicable law; PROVIDED HOWEVER, that either Party may disclose the
terms or conditions of this Agreement to a third party under an obligation of
confidentiality to such Party in connection with a proposed sale or in the event
of a proposed merger, change in control, consolidation, an equity investment by
such third party in such Party or other similar transaction. Notwithstanding the
foregoing, GLAXO and DELTAGEN shall agree upon the substance of information that
can be used to describe the existence and/or terms of this transaction in a
press release and GLAXO and DELTAGEN shall have the right to disclose such
information, as such information may be modified by mutual agreement of the
parties from time to time.

         5.4      RETURN OF CONFIDENTIAL INFORMATION. Except as expressly
provided in this Agreement or in a particular Scope of Work, nothing herein
shall be construed as giving either Party any license, right, title or interest
in or ownership of the other Party's Confidential Information, whether express
or implied. Upon termination of this Agreement or a particular Project as
provided in Article 11, a Party shall return all Confidential Information of the
other Party and/or destroy any portion of any documents, computer records, notes
and other material retained by such Party containing the Confidential
Information of the other Party. However, each Party may retain one copy of such
Confidential Information in its legal files to be used only for interpretation
of and compliance with this Agreement.

6.       REPRESENTATIONS AND WARRANTIES.

         6.1      MUTUAL REPRESENTATIONS AND WARRANTIES. Subject to the other
provisions of this Article 6, each Party hereby represents and warrants to the
other Party as follows:

                  6.1.1    Such Party is a corporation duly organized, validly
existing and in good standing under the laws of the state in which it is
incorporated.

                  6.1.2    Such Party (a) has the corporate power and authority
and the legal right to enter into this Agreement and to perform its obligations
hereunder, and (b) has taken all necessary corporate action on its part to
authorize the execution and delivery of this Agreement and the performance of
its obligations hereunder. This Agreement has been duly executed and delivered
on behalf of such Party, and constitutes a legal, valid, binding obligation,
enforceable

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       8
<PAGE>

against such Party in accordance with its terms.

                  6.1.3    All necessary consents, approvals and authorizations
of all governmental authorities and other persons required to be obtained by
such Party in connection with this Agreement have been obtained.

                  6.1.4    The execution and delivery of this Agreement and the
performance of such Party's obligations hereunder (a) do not conflict with or
violate any requirement of applicable laws or regulations, and (b) do not
conflict with, result in a breach of any of the terms and provisions of, or
constitute a default under, any contractual obligation of it, and (c) do not
conflict with or result in a breach of any of the terms and provisions of its
charter or operative documents or bylaws.

                  6.1.5    Such Party shall comply with all applicable material
laws and regulations related to its activities contemplated under this
Agreement.

         6.2      DELTAGEN TECHNOLOGY. DELTAGEN represents and warrants *** that
DELTAGEN (a) is the owner or licensee of the DELTAGEN Technology and (b) has the
***.

         6.3      GLAXO TECHNOLOGY. GLAXO represents and warrants that (a) ***
it is the owner or licensee of the GLAXO Technology and (b) it has the right to
provide the *** and information relating thereto to DELTAGEN and ***.

         6.4      LIMITATION OF WARRANTY AND LIABILITY. EXCEPT AS OTHERWISE
EXPRESSLY SET FORTH IN THIS AGREEMENT, DELTAGEN MAKES NO WARRANTIES, EXPRESS OR
IMPLIED, WITH RESPECT TO THE STANDARD KNOCKOUT MICE, CONDITIONAL KNOCKOUT MICE,
KNOCK-IN MICE OR DATA GENERATED UNDER THIS AGREEMENT OR THE PROJECTS AND
DELTAGEN DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT
LIMITATION IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR LOSS OF
PROFITS OR INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES DIRECTLY OR INDIRECTLY
ARISING OUT OF THIS AGREEMENT OR THE RESEARCH, DEVELOPMENT, GENERATION OR USE OF
THE STANDARD KNOCKOUT MICE, CONDITIONAL KNOCKOUT MICE, KNOCK-IN MICE OR DATA
GENERATED UNDER THIS AGREEMENT. Except as specifically provided in Section 2.8,
all Standard Knockout Mice, Conditional Knockout Mice and Knock-In Mice
generated pursuant to this Agreement are delivered to and will be accepted by *
* *.

         6.5      RESPONSIBILITY FOR SELECTION OF GENE SEQUENCE AND RESULTING
STANDARD KNOCKOUT MICE, CONDITIONAL KNOCKOUT MICE OR KNOCK-IN MICE.
Notwithstanding anything to the contrary in this Agreement, GLAXO acknowledges
and agrees that (a) each gene sequence (or portion thereof) that is the subject
of a Project is solely selected by GLAXO and GLAXO shall be solely responsible
for selecting and providing DELTAGEN with such specific gene sequences for each
Project. Consequently, GLAXO shall solely bear the risk for any Claims (defined
in Section 12.1 below) relating to *** Standard Knockout Mice, Conditional
Knockout Mice or Knock-In Mice generated under this Agreement and (b) DELTAGEN's
representations and warranties under this Article 6 shall not apply or relate to
the identification, selection or use of the specific gene sequences for any
Project under this Agreement or any Standard Knockout Mice, Conditional Knockout
Mice, Knock-In Mice or Data arising from the deletion, interruption or
disruption of

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       9
<PAGE>

such gene sequences .

7.       REPORTING. Unless another method of reporting is specified in the
applicable Scope of Work, DELTAGEN shall deliver via overnight delivery service
(or other reasonable means agreed to by the parties) to the GLAXO Representative
all reports required to be delivered in connection with a Project.

8.       RECORD RETENTION, INSPECTIONS AND COOPERATION.

         8.1      RETENTION BY DELTAGEN. At GLAXO'S request, DELTAGEN shall
maintain all written Data and reports from each Project for a period of one (1)
year from the date of completion of such Project. At the expiration of such one
(1) year period, GLAXO, at GLAXO's cost and expense, shall arrange with DELTAGEN
for delivery of such Data to GLAXO or DELTAGEN may dispose of such written Data
sixty (60) days after providing written notice of the same to GLAXO.

         8.2      GOVERNMENTAL AUDITS. If a federal, state or local government
authority conducts or gives notice of its intent to conduct an inspection or
takes regulatory action with respect to a Project conducted under this
Agreement, the Party learning thereof shall reasonably notify in writing the
other Party thereof and each Party shall provide the other with any information
reasonably required in connection therewith.

9.       DATA. Notwithstanding the provisions of Section 8, for each Project,
DELTAGEN shall prepare and submit to GLAXO or its designee the Data set forth
under the applicable Scope of Work with respect to a particular Project within
forty-five (45) days after (i) the date of termination or completion of the
Milestones on the Scope of Work for such Project or, if later, (ii) the date
GLAXO requests for delivery of such Data.

10.      SUBCONTRACTING AND INDEPENDENT CONTRACTOR.

         10.1     SUBCONTRACTING. GLAXO is aware that certain Projects may
require DELTAGEN to subcontract to third parties portions of the work required
under a Scope of Work. GLAXO shall be deemed to have approved such
subcontracting on the following terms and conditions: (i) DELTAGEN shall not be
allowed or authorized to make any representations relating to GLAXO without the
prior written consent of GLAXO; and (ii) such third party subcontractor shall be
subject to the terms and conditions of this Agreement. Prior to subcontracting
any work contemplated by a Project, DELTAGEN shall notify GLAXO of the intended
third party subcontractor and ***, DELTAGEN may subcontract such work under the
Scope of Work to such third party subcontractor. If GLAXO does object to the use
of a particular subcontractor, in its sole discretion, DELTAGEN shall be
prohibited from using such subcontractor to perform work under this Agreement
and DELTAGEN may terminate the affected Project(s) without penalty if DELTAGEN
determines in its reasonable discretion that its ability to timely complete the
Project(s) within Budget is materially and adversely affected by such
prohibition.

         10.2     INDEPENDENT CONTRACTOR. DELTAGEN shall perform its obligations
under this Agreement as an independent contractor and nothing contained herein
shall be construed to be inconsistent with that relationship or status. Neither
Party, nor their officers, directors, employees or agents shall be considered
employees or agents of the other Party and

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       10
<PAGE>

shall not be entitled to participate in any of the other Party's benefit plans,
programs, employment policies, or workers' compensation insurance. This
Agreement shall not constitute, create, or in any way be interpreted as a joint
venture, partnership or business organization of any kind. Neither Party shall
have the authority to bind the other Party to any agreement whatsoever.

11.      TERM AND TERMINATION.

         11.1     TERM. This Agreement shall commence on the Agreement Date and
remain in full force and effect, unless earlier terminated as provided below in
this Article 11, until the latest of (a) two (2) years after the Agreement Date,
(b) the completion by DELTAGEN of all Milestones under any Projects commenced
under this Agreement, or ***, unless otherwise agreed between the Parties.

         11.2     TERMINATION BY GLAXO. GLAXO shall have the right to terminate
this Agreement or a Project at any time without cause, upon *** prior written
notice.

         11.3     TERMINATION BY DELTAGEN. DELTAGEN shall have the right to
terminate any Project upon DELTAGEN's identification of an item or
circumstance under Section 2.4 or 10.1 that would prevent DELTAGEN from
completing such Project using commercially reasonable efforts by providing
*** written notice to GLAXO, which notice shall contain the basis for such
termination.

         11.4     TERMINATION BY EITHER PARTY.

                  11.4.1   Except as otherwise provide in Article 14 below, this
Agreement or a Project may be terminated by either Party upon any material
breach of this Agreement by the other Party, provided that any breaching Party
shall be given not less than ***) prior written notice of such breach and the
opportunity to cure such breach during such period.

                  11.4.2   This Agreement or a Project may be immediately
terminated by either Party if the other Party is dissolved or liquidated, files
or has filed against it a petition in bankruptcy or has a receiver appointed for
a substantial part of its assets.

         11.5     RIGHTS AND OBLIGATIONS AFTER NOTICE OF TERMINATION.

                  11.5.1   If this Agreement is terminated either by GLAXO
pursuant to Section 11.2 or by DELTAGEN pursuant to Section 11.4, then DELTAGEN
shall cease further work on all Projects. If a Project is terminated by GLAXO
pursuant to Section 11.2, then DELTAGEN shall cease further work on the
terminated Project and shall have the right to cease further work on any or all
other Projects.

                  11.5.2   If a Project is terminated by DELTAGEN pursuant to
Section 11.3, then DELTAGEN shall cease further work on the terminated Project.
If this Agreement is terminated by GLAXO pursuant to Section 11.4, then DELTAGEN
shall cease further work on all Projects.

                  11.5.3   In the event of any termination of this Agreement or
a Project, then

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       11
<PAGE>

with respect to the affected Project(s):

                           11.5.3.1 DELTAGEN may endeavor to cancel, if
permitted under the terms of applicable agreements, any third party obligations
that relate thereto.

                           11.5.3.2 Within *** after DELTAGEN's cessation of
work thereon, DELTAGEN shall provide GLAXO with a written statement of all work
performed by it through termination, including any non-cancelable costs or
expenses incurred by DELTAGEN prior to termination. Subject to the next
sentence, (i) DELTAGEN shall invoice GLAXO for all Milestones completed by
DELTAGEN and for all reasonable non-cancelable costs or expenses and (ii) if
such notice is received by DELTAGEN after work has commenced but prior to
DELTAGEN's completion of work under a Milestone, DELTAGEN shall invoice GLAXO
for payment of such uncompleted Milestone as if DELTAGEN had completed such
Milestone and GLAXO shall pay DELTAGEN for such uncompleted Milestone. ***,
however, *** to the work performed and/or Milestones completed that constitute
such breach by DELTAGEN and ***.

                           11.5.3.2 Within sixty (60) days of DELTAGEN'S or
GLAXO's notice of termination, as the case may be, DELTAGEN shall deliver to
GLAXO all unused Study Materials and GLAXO Technology generated under such
Project.

                           11.5.3.3 Within thirty (30) days after payment to
DELTAGEN of all amounts due hereunder, DELTAGEN shall deliver to GLAXO (i) all
Project Mice generated under such Project up to the date of termination, *** or
generated by DELTAGEN or its subcontractors from those particular animals in the
course of performing such Project, and (ii) all phenotypic data and information
with respect to the Project Mice, in each case subject to Sections 4.3.1 through
4.3.

         11.6     EFFECT OF EXPIRATION OR TERMINATION. Expiration or termination
of this Agreement shall not relieve the parties of any obligation accruing prior
to such expiration or termination. The provisions of Sections 6.4, 6.5, and 11.5
and Articles 1, 3 (with respect to periods prior to termination), 4, 5, 7, 8, 12
and 16 shall survive any expiration or termination of this Agreement.

12.      INDEMNIFICATION.

         12.1     GLAXO'S INDEMNIFICATION. GLAXO shall defend, indemnify and
hold harmless DELTAGEN and its directors, officers, employees and agents from
and against any and all losses, liabilities, damages or expenses (collectively,
"Liabilities") that they may suffer as a result of any claims, demands, actions
or other proceedings (collectively, "Claims") made or instituted by any third
party and arising out of or relating to (a) a breach of any representation,
warranty or covenant of GLAXO under this Agreement or (b) GLAXO's gross
negligence or willful misconduct, except in each case to the extent such
Liabilities resulted from the gross negligence or willful misconduct of
DELTAGEN.

         12.2     DELTAGEN'S INDEMNIFICATION. DELTAGEN shall defend, indemnify
and hold harmless GLAXO and its directors, officers, employees and agents from
and against any and all Liabilities that they may suffer as a result of any
Claims made or instituted by any third party and arising out of or relating to
(a) a breach of any representation, warranty or covenant of

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       12
<PAGE>

DELTAGEN under this Agreement or (b) DELTAGEN's gross negligence or willful
misconduct, except in each case to the extent such Liabilities resulted from the
gross negligence or willful misconduct of GLAXO.

         12.3     PROCEDURE. A Party (the "Indemnified Party") which intends to
claim indemnification under this Article 12, shall promptly notify the other
Party (the "Indemnifying Party") of any Claim with respect to which the
Indemnified Party intends to claim such indemnification. The Indemnifying Party
shall have the right to assume the defense of such Claim with counsel selected
by the Indemnifying Party; PROVIDED, HOWEVER, that the Indemnified Party shall
have the right to retain its own counsel and the fees and expenses shall be paid
by the Indemnifying Party only if representation of the Indemnified Party by the
counsel retained by the Indemnifying Party would be inappropriate due to actual
or potential differing interests between the Indemnified Party and any other
party represented by such counsel in such proceedings. The indemnity obligations
under this Article 12 shall not apply to amounts paid in settlement of any
Liability if such settlement is effected without the consent of the Indemnifying
Party, which consent shall not be withheld unreasonably. The failure of the
Indemnified Party to promptly notify the Indemnifying Party of a potential Claim
shall not constitute a waiver of, or result in the loss of, such Party's right
to indemnification under this Section 12.3, except to the extent that the
Indemnifying Party's rights and/or its ability to defend such Claim is
prejudiced by the Indemnified Party's failure to notify the Indemnifying Party
of such Claim within a reasonable time after the commencement of any action. The
Indemnifying Party may not settle the action or otherwise consent to an adverse
judgment in such action that diminishes the rights or interests of the
Indemnified Party without the express written consent of the Indemnified Party,
which consent shall not be withheld unreasonably. The Indemnified Party, its
employees and agents, shall cooperate fully with the Indemnified Party and its
legal representatives in the investigation of any Claim covered by this
indemnification.

13.      TRADEMARKS AND PUBLICITY. Except as set forth in Section 5.3 above,
each Party agrees not to identify the other Party or any Affiliate of the other
Party in any promotion advertising or other promotion materials to be
disseminated to the public, or to use any trademark, service mark, trade name or
symbol of the other Party or any Affiliate of the other Party without the
express written consent of the other Party.

14.     DELAYS OR FORCE MAJEURE.

         14.1     FORCE MAJEURE. Neither Party shall be liable for the failure
or delay to perform its obligations under this Agreement or a Project if such
failure or delay is caused by or results from causes beyond such Party's
reasonable control, including but not limited to strikes or other labor
disturbances, embargoes, acts of God, omissions or delays in acting by any
governmental authority or the other party, lockouts, riots, wars, fires, floods,
earthquakes or storms. A Party claiming a right to excused performance under
this Section 14.1 shall immediately notify the other Party in writing of the
extent of its inability to perform, which notice shall specify the occurrence
beyond its reasonable control that prevents such performance, and such Party
shall exert reasonable efforts to eliminate, cure and overcome any such causes
and to promptly resume performance of its obligations under this Agreement.

         14.2     DELAY. If GLAXO delays in performing its obligations under a
Project for any

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       13
<PAGE>

reason, the estimated date that DELTAGEN is targeted to complete its duties and
obligations as described in the applicable Scope of Work shall be extended by
the period of time corresponding to the delay provided always that DELTAGEN
gives GLAXO reasonable notice of the reason for the delay.

15.      NOTICES. Any notice required or permitted to be given hereunder by one
of the parties hereto to the other party shall be in writing and delivered by
any lawful means to the address of the other party set forth below or at such
other address as either Party hereto may designate in writing. If sent by
facsimile letter, notice shall be deemed given when the transmission is
completed if the sender has a confirmed transmission report. Any notice sent by
facsimile must also be sent by mail or overnight courier or delivered by hand.

IF TO DELTAGEN:

Deltagen, Inc.
1003 Hamilton Avenue
Menlo Park, CA 94025
Fax:   (650) 752-0202
Attn:  President

With a copy to the above address,
Attn:  General Counsel
Fax:   (650) 752-0220

IF TO GLAXO:

GLAXO GROUP LIMITED
Glaxo Wellcome House

Berkeley Avenue
Greenford
Middlesex UB6 ONN
United Kingdom
Fax:  (0044) (0)208 966 8837
Attn: The Company Secretary,

16.     MISCELLANEOUS

         16.1     ASSIGNMENT. Except as otherwise expressly provided under this
Agreement, neither this Agreement nor any right or obligation hereunder may be
assigned or otherwise transferred (whether voluntarily, by operation of law or
otherwise), without the prior express written consent of the other party;
provided, however, that either party may (in the absence of "good reason" as
defined in Section 9.5.1 of the Collaboration Agreement), assign this Agreement
and its rights and obligations hereunder in connection with the transfer or sale
of all or substantially all of its business, or in the event of its merger,
consolidation, change in control or similar transaction. Any permitted assignee
shall assume all obligations of its assignor under this Agreement. Any purported
assignment or transfer in violation of this Section 16.1 shall be

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       14
<PAGE>

void.

         16.2     AMENDMENTS; WAIVER. No provision of this Agreement, a Budget
or a Scope of Work may be amended, modified, revoked, or waived except in
writing signed and delivered by an authorized officer of each Party. Either
Party's failure to require the other Party to comply with the provisions of this
Agreement shall not be deemed a waiver of such provision or any other provision
of this Agreement.

         16.3     VALIDITY. If any clause, section or paragraph of this
Agreement is determined by a court of competent jurisdiction to be illegal,
invalid or unenforceable, it will be deemed severed from the remainder of this
Agreement and will have no effect on the legality, validity or enforceability of
the remaining provisions.

         16.4     HEADINGS. The paragraph headings of this Agreement are merely
for the convenience of the parties and are not to be construed as modifying or
changing the obligations or conditions expressed in this Agreement.

         16.5     ENTIRETY. This Agreement (including the Attachments hereto)
represents the entire understanding as of the Agreement Date hereof between the
parties with respect to the matter hereof and supersedes all prior agreements,
negotiations, understandings, representations, statements and writings between
the parties relating thereto.

         16.6     CONFLICT WITH SCOPE OF WORK OR BUDGET. If any terms of this
Agreement are in conflict with any terms of any Scope of Work or Budget, the
terms of this Agreement shall govern.

         16.7     COUNTERPARTS. This Agreement may be executed in several
counterparts, each of which shall be deemed an original but all of which shall
constitute one and the same instrument.

         16.8     GOVERNING LAW. This Agreement shall be governed by and
construed in accordance with the laws of ***, without regard to its conflicts of
law principles.

         16.9     FURTHER ACTIONS. Each Party agrees to execute, acknowledge and
deliver such further instruments, and to do all other acts, as may be necessary
or appropriate in order to carry out their obligations under this Agreement.

        IN WITNESS WHEREOF, the Parties hereto through each of their respective
duly authorized representatives have caused this Agreement to be executed as of
the Agreement Date.

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       15
<PAGE>

<TABLE>
<S>                                         <C>
GLAXO GROUP LIMITED                         DELTAGEN, INC.

By:  /s/ F. M. Bicknell                     By: /s/ William Matthews
   ---------------------------------           -----------------------------------------

Name: F.M. Bicknell                         Name: William Matthews
     -------------------------------             ---------------------------------------

Title: Assistant Corporate Secretary        Title: President and Chief Executive Officer
      ------------------------------              --------------------------------------

GLAXO RESEARCH AND
DEVELOPMENT LIMITED

By: /s/ F. M. Bicknell
   ---------------------------------

Name: F.M. Bicknell
     -------------------------------

Title: Corporate Secretary
      ------------------------------
</TABLE>

                                       16
<PAGE>

                                  ATTACHMENT I

                            SCOPE OF WORK AND BUDGET

               SCIENTIFIC MILESTONES AND PAYMENT SCHEDULE FOR ***

         Payments to DELTAGEN shall be based on the achievement of the specific
Milestones for each Project as outlined below. GLAXO understands and
acknowledges that each Project involves a number of technologically complex
steps and that any time periods for performance are reasonable estimates only
and subject to change due to technological difficulties encountered. DELTAGEN
shall be obligated to notify GLAXO of any such technical difficulties as soon as
reasonably possible after they arise and the parties will commence good faith
discussions to resolve such technical difficulties in a reasonable manner.

STANDARD KNOCKOUT MICE PROJECTS

<TABLE>
<S>                                                                             <C>
Total cost for each Standard Knockout Mice Project:                             $75,000.00

The following payments are per each Standard Knockout Mice Project:

***                                                                             ***

***                                                                             ***

***                                                                             ***

***                                                                             ***
</TABLE>

If requested by GLAXO, the following additional services would be provided at
the additional costs set forth below:

         For *** analysis of the resulting Standard Knockout Mice, an additional
payment of ***;

         For *** of an *** after *** of the *** under Milestone 1 below,
DELTAGEN would perform Milestones 1 and 2 as follows: For *** clones based upon
such *** (up to ***), an additional payment negotiated on a case-by-case basis
(***) (the "*** Milestone"); and

         For *** beyond the *** by DELTAGEN as set forth in Milestone 2 (other
than screening associated with the New Targeting ***), DELTAGEN ***at GLAXO's
request for an additional cost of *** for each *** (the "***").

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       17
<PAGE>

PAYMENT MILESTONES FOR A STANDARD KNOCKOUT MICE PROJECT

The Milestones for a Standard Knockout Project would be as follows:

MILESTONE 1: ***. DELTAGEN will *** based on *** received from GLAXO. The cost
of *** is included in the initiation payment paid by GLAXO. GLAXO will receive
*** information in order to confirm the gene ***in the ***. In the event of
unforeseen technical difficulties encountered after *** relating to the ***,
either (a) DELTAGEN would, upon consultation with GLAXO, *** at no additional
cost to GLAXO (one time), (b) GLAXO could terminate the particular Project or
(c) GLAXO could request that ***. *** would be provided at costs set forth in
the *** Milestone above.

***. DELTAGEN would *** and select ***. DELTAGEN would *** up to *** for
identification of at least *** and a maximum of up to ***. In the event that
DELTAGEN is only able to *** and GLAXO requests that DELTAGEN ***, or if ***
within the *** of the ***, DELTAGEN, after consultation with GLAXO, would either
(a) *** and *** and *** up to an additional *** at the costs specified for the
*** Milestone or (b) *** at the costs specified for the *** Milestone. The ***
would be analyzed through ***. GLAXO would also receive *** in order to confirm
the ***.

MILESTONE 2: ***. DELTAGEN would *** a minimum of *** and up to a maximum of ***
mice. DELTAGEN would provide to GLAXO by delivery FOB GLAXO's designated
carrier, either *** mice or *** mice. GLAXO shall promptly and reasonably
confirm *** using ***. If *** reasonably demonstrates that *** with the *** mice
or *** provided by DELTAGEN to GLAXO, DELTAGEN would provide to GLAXO *** mice
or *** capable of ***, provided that GLAXO properly and reasonably conducted
***. Prior to DELTAGEN providing such additional *** mice or ***, GLAXO would
demonstrate to DELTAGEN's reasonable satisfaction that ***.

GLAXO would have the right to terminate a particular Standard Knockout Mice
Project at any time (after payment in full of the next applicable Milestone
payment) but without further obligation to proceed with additional Milestones
with respect to the particular Standard Knockout Mice Project).

STARTING MATERIALS FOR A STANDARD KNOCKOUT MICE PROJECT

The costs set forth above would be dependent upon GLAXO providing to DELTAGEN
the following "Starting Materials" for Standard Knockout Mice Projects and GLAXO
would be responsible for providing to DELTAGEN such Starting Materials in order
for DELTAGEN to undertake a Standard Knockout Mice Project at such costs. The
Starting Materials for a Standard Knockout Mice Project shall be *** reasonably
required by Deltagen as mutually agreed to by the parties for Deltagen to
commence Milestone 1 above.

CONDITIONAL KNOCKOUT MICE PROJECTS ***

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       18
<PAGE>

<TABLE>
<S>                                                                             <C>
Total cost for each *** Conditional Knockout Mice Project:                      $65,000.00

The following Milestone payments are per each *** Conditional Knockout Mice
Project:

Milestone 1 ***                                                                 ***

Milestone 2 ***                                                                 ***

Milestone 3 ***                                                                 ***

Milestone 4 ***                                                                 ***
</TABLE>

If requested by GLAXO, the following additional services would be provided at
the additional costs set forth below:

         For ***and *** analysis of mice generated/provided under a Conditional
Knockout Mice Project, an additional payment of ***;

         For *** analysis of mice generated/provided under a Conditional
Knockout Mice Project, an additional payment of ***.

Total cost for each *** Mouse in a Conditional Knockout Mice Project:

         Available *** Mouse - Where DELTAGEN has the *** Mouse in its
possession and DELTAGEN has the *** Mouse to GLAXO, the cost for such Cre Mouse
shall be ***

         Custom *** Mouse - Where DELTAGEN is required to design, generate and
deliver such *** Mouse to GLAXO, the cost for such *** Mouse shall be $50,000.00

The following Milestone payments are per each *** Mouse Conditional Knockout
Mice Project:

<TABLE>
<S>                                                                             <C>
Milestone 1 ***                                                                 ***

Milestone 2 ***                                                                 ***

Milestone 3 ***                                                                 ***

Milestone 4 ***                                                                 ***
</TABLE>

If requested by GLAXO, the following additional services would be provided at
the costs set forth below:

         For *** and *** analysis of mice generated/provided under a Conditional
Knockout Mice Project, an additional payment of ***;

         For *** analysis of mice generated/provided under a Conditional
Knockout Mice Project, an additional payment of ***.

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       19
<PAGE>

PAYMENT MILESTONES FOR A CONDITIONAL KNOCKOUT MICE PROJECT

The Milestones for a Conditional Knockout Mice Project would be as follows:

MILESTONE 1: ***. DELTAGEN will commence the project after reviewing the ***
provided by GLAXO. These include:

         ***;

         *** relating to ***; and

         ***.

         If DELTAGEN determines that there is insufficient information or
materials to commence the project, DELTAGEN will discuss with GLAXO the steps
that DELTAGEN believes are reasonably necessary to obtain the needed information
or materials.

MILESTONE 2: ***. DELTAGEN would *** based on *** that would be provided to
DELTAGEN by GLAXO. In the event of unforeseen technical difficulties encountered
after *** relating to ***, either (a) DELTAGEN would, upon consultation with
GLAXO *** at no additional cost to GLAXO (one time), (b) GLAXO could terminate
the particular Conditional Knockout Mice Project or (c) GLAXO could request that
DELTAGEN ***). *** would be provided at the costs set forth in the *** Milestone
above.

Completion of this milestone will be determined by *** to confirm the ***.
DELTAGEN will provide *** to GLAXO for approval.

MILESTONE 3: ***. DELTAGEN would *** and ***. DELTAGEN would *** up to *** for
identification of at least *** and a maximum of up to ***. In the event that
DELTAGEN is only able to identify *** and GLAXO requests that DELTAGEN identify
***, or if *** within the initial *** of the ***, DELTAGEN, after consultation
with GLAXO, would either (a) *** and *** with the *** and *** up to *** at the
costs specified for the *** Milestone or (b) *** at the costs specified for the
*** Milestone. The identification of a *** would be analyzed through ***.

MILESTONE 4: ***. DELTAGEN would *** a minimum of *** and up to a maximum of ***
mice. DELTAGEN would provide to GLAXO by delivery FOB GLAXO's designated
carrier, either *** mice or *** mice. GLAXO shall promptly and reasonably
confirm *** using ***. If *** reasonably demonstrates that *** with the *** mice
or *** provided by DELTAGEN to GLAXO, DELTAGEN would provide to GLAXO *** mice
or ***, provided that GLAXO properly and reasonably conducted ***. Prior to
DELTAGEN providing such *** mice or ***, GLAXO would demonstrate to DELTAGEN's
reasonable satisfaction ***.

GLAXO would have the right to terminate a particular Conditional Knockout Mice
Project at any time (after payment in full of the next applicable Milestone
payment) but without further obligation to proceed with additional Milestones
with respect to the particular Conditional Knockout Mice Project).

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       20
<PAGE>

STARTING MATERIALS FOR A CONDITIONAL KNOCKOUT MICE PROJECT

The costs set forth above would be dependent upon GLAXO providing to DELTAGEN
the following "Starting Materials" for Conditional Knockout Mice Projects and
GLAXO would be responsible for providing to DELTAGEN such Starting Materials in
order for DELTAGEN to undertake a Conditional Knockout Mice Project at such
costs. The Starting Materials for a Conditional Knockout Mice Project are the
following materials and information:

         ***

                  -- The ***

         The ***

                  -- GLAXO would also need to provide all ***

         *** for the *** by DELTAGEN

KNOCK-IN MICE PROJECT

<TABLE>
<S>                                                                             <C>
Total cost for each Knock-In Mice Project:                                      $75,000.00

The following payments are per each Knock-In Mice Project:

Milestone 1 ***                                                                 ***

Milestone 2 ***                                                                 ***

Milestone 3 - ***                                                               ***

Milestone 4 ***                                                                 ***
</TABLE>

If requested by GW, the following additional services would be provided at the
additional costs set forth below:

         For *** and *** analysis of mice generated/provided under a Knock-In
Mice Project, a payment of ***;

         For *** analysis of mice generated/provided under a Knock-In Mice
Project, a payment of ***.

PAYMENT MILESTONES FOR A KNOCK-IN MICE PROJECT

The Milestones for a Knock-In Mice Project would be as follows:

MILESTONE 1 ***. DELTAGEN will commence the project after reviewing the *** and
***

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       21
<PAGE>

provided by GLAXO.

If DELTAGEN determines that there is insufficient information or materials to
commence the project, DELTAGEN will discuss with GLAXO what steps are reasonably
necessary to obtain the needed information or materials.

MILESTONE 2: ***. DELTAGEN would *** based on *** that would be provided to
DELTAGEN by GLAXO. In the event of unforeseen technical difficulties encountered
after *** relating to the ***, either (a) DELTAGEN would, upon consultation with
GLAXO, *** at no additional cost to GLAXO (one time), (b) GLAXO could terminate
the particular Knock-In Mice Project or (c) GLAXO could request that DELTAGEN
***). *** would be provided at the costs set forth in the *** Milestone above.

Completion of this milestone will be determined by *** to confirm the ***.
DELTAGEN will provide this *** to GLAXO for approval.

MILESTONE 3: ***. DELTAGEN would *** and ***. DELTAGEN would *** up to *** for
identification of at least *** and a maximum of up to *** that have undergone
***. In the event that DELTAGEN is only able to *** and GLAXO requests that
DELTAGEN identify ***, or if *** within the *** of the ***, DELTAGEN, after
consultation with GLAXO, would either (a) *** and *** and *** up to *** at the
costs specified for the *** Milestone or (b) *** at the costs specified for the
*** Milestone. The identification of a *** would be analyzed through ***.

MILESTONE 4: ***. DELTAGEN would *** a minimum of *** and up to a maximum of ***
*** mice. DELTAGEN would provide to GLAXO by delivery FOB GLAXO's designated
carrier, either *** mice or *** mice. GLAXO shall promptly and reasonably
confirm *** using ***. If *** reasonably demonstrates *** has occurred with the
*** or *** provided by DELTAGEN to GLAXO, DELTAGEN would provide to GLAXO ***
mice or ***, provided that GLAXO properly and reasonably conducted ***. Prior to
DELTAGEN providing *** mice or ***, GLAXO would demonstrate to DELTAGEN's
reasonable satisfaction ***.

GLAXO would have the right to terminate a particular Knock-In Mice Project at
any time (after payment in full of the next applicable Milestone payment) but
without further obligation to proceed with additional Milestones with respect to
the particular Knock-In Mice Project).

STARTING MATERIALS FOR A KNOCK-IN MICE PROJECT

The costs set forth above would be dependent upon GLAXO providing to DELTAGEN
the following "Starting Materials" for Knock-In Mice Projects and GLAXO would be
responsible for providing to DELTAGEN such Starting Materials in order for
DELTAGEN to undertake a Knock-In Mice Project at such costs. The Starting
Materials for a Knock-In Mice Project are the following materials and
information:

         ***

                  -- The ***

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       22
<PAGE>

         The ***

                  -- GLAXO would also need to provide all *** events

         *** for the *** by DELTAGEN

[***] Confidential Treatment Requested. The confidential portions have been
filed separately with the Securities & Exchange Commission.

                                       23
<PAGE>

                                  ATTACHMENT II

            FORM NOTIFICATION LETTER FOR INITIATION OF A NEW PROJECT

                               (Template follows)

                                       24
<PAGE>

                               (GLAXO letterhead)

________________, _____

William Matthews, Ph.D.
President
Deltagen, Inc.
1003 Hamilton Avenue
Menlo Park, CA 94025

Dear Bill,

This letter is to provide notice to DELTAGEN of GLAXO's request to DELTAGEN to
initiate work on a Project under the terms and conditions of the DeltaSelect-TM-
Collaborative Services Agreement between DELTAGEN, Inc. and GLAXO, dated
______________ (the "Agreement"), including but not limited to, the
confidentiality obligations of the Agreement.

The Project to be initiated is described as follows:

The GLAXO contact scientist for technical information regarding the Project will
be:

GLAXO requests that DELTAGEN begin to work to develop the above described
Project on the terms and conditions of the above-referenced Agreement.

Sincerely,

[GLAXO RESEARCH INSTITUTE'S Signatory]

Agreed,

________________________
Deltagen, Inc.

                                       25

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