EXHIBIT 4.3


                         COMMON STOCK PURCHASE AGREEMENT

     THIS COMMON STOCK PURCHASE AGREEMENT ("Agreement") is made and entered into
as of May 14, 2007 (the "Effective Date"), by and between GERON CORPORATION, a
Delaware corporation having its principal place of business at 230 Constitution
Drive, Menlo Park, California 94025 ("Geron"), and Girindus America Inc., a
Delaware corporation having its principal place of business at 8560 Reading
Road, Cincinnati, Ohio, 45215 ("Manufacturer").

          A.   Geron and Manufacturer are the parties to that certain Master
               Manufacturing Agreement dated as of February 27, 2007 (the
               "Manufacturing Agreement"), and related Project Orders ("Project
               Order") under which Geron has agreed to purchase certain products
               from Manufacturer and Manufacturer has agreed to supply such
               products to Geron on the terms set forth therein.

          B.   Pursuant to the Manufacturing Agreement, Geron may pay the
               purchase price of products under any Project Order by delivery of
               shares of Geron's Common Stock (the "Shares").

THE PARTIES AGREE AS FOLLOWS:

     1.   ISSUANCE OF SHARES; ADJUSTMENTS.

          1.1  As payment of the First Installment specified in Project Order
               No. 1, Geron will issue and deliver certificates for 204,082
               Shares. Upon issuance and delivery of the certificate(s) for the
               Shares, all Shares shall be duly authorized and validly issued
               and represent fully paid shares of Geron's Common Stock.

     2.   CLOSING; DELIVERY.

          2.1  The consummation of the transaction contemplated by this
               Agreement (a "Closing") shall be held at such time and place as
               is mutually agreed upon between the parties, but in any event
               Geron shall make commercially reasonable efforts to accomplish
               the Closing no later than three (3) business days after the
               Effective Date hereof (the "Closing Date"). At the Closing, Geron
               shall deliver to Manufacturer one or more certificates
               representing all of the Shares, which Shares shall be issued in
               the name of Manufacturer or its designee and in such
               denominations as Manufacturer shall specify.

          2.2  Geron's obligations to issue and deliver the stock certificate(s)
               representing the Shares to Manufacturer at the Closing shall be
               subject to the following conditions, which may be waived by
               Geron:

               2.2.1 the covenants and obligations that Manufacturer is required
                    to perform or to comply with pursuant to this Agreement, at
                    or prior to the Closing, must have been duly performed and
                    complied with in all material respects; and

               2.2.2 the representations and warranties made by Manufacturer
                    herein shall be true and correct in all material respects as
                    of the Closing Date.

          2.3  Manufacturer's obligation to accept delivery of the stock
               certificate(s) representing the Shares at the Closing shall be
               subject to the following conditions, any one or more of which may
               be waived by Manufacturer:

               2.3.1 the covenants and obligations that Geron is required to
                    perform or to comply with pursuant to this Agreement, at or
                    prior to the Closing, must have been duly performed and
                    complied with in all material respects;

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               2.3.2 Geron shall have available under its Certificate of
                    Incorporation sufficient authorized shares of Common Stock
                    to issue the Shares to Manufacturer; and

               2.3.3 the representations and warranties made by Geron herein
                    shall be true and correct in all material respects as of the
                    closing date;

     3.   RESTRICTIONS ON RESALE OF SHARES.

          3.1  Legends. Manufacturer understands and acknowledges that the
               Shares are not registered under the Securities Act of 1933 (the
               "Act"), and that under the Act and other applicable laws
               Manufacturer may be required to hold such Shares for an
               indefinite period of time. Each stock certificate representing
               Shares shall bear the following legends:

               "THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER
               THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"). ANY TRANSFER
               OF SUCH SECURITIES SHALL BE INVALID UNLESS A REGISTRATION
               STATEMENT UNDER THE ACT IS IN EFFECT AS TO SUCH TRANSFER OR, IN
               THE OPINION OF COUNSEL REASONABLY ACCEPTABLE TO GERON, SUCH
               REGISTRATION IS UNNECESSARY FOR SUCH TRANSFER TO COMPLY WITH THE
               ACT. THE SECURITIES REPRESENTED HEREBY ARE SUBJECT TO THE TERMS
               OF THE COMMON STOCK PURCHASE AGREEMENT BY AND BETWEEN
               MANUFACTURER AND GERON, DATED AS OF MAY 14, 2007. A COPY OF THE
               AGREEMENT CAN BE OBTAINED FROM THE SECRETARY OF GERON."

          3.2  Limits on Sales. Manufacturer agrees that if it decides to resell
               some or all of the Shares, it will do so only through orderly
               sales executed through a reputable brokerage house, and in an
               appropriate manner based upon whether the shares are registered
               or unregistered, i.e., on the Nasdaq National Market or in a Rule
               144A or Rule 144 compliant transaction. Manufacturer further
               agrees that it will not itself engage in short selling with
               respect to the Stock. Provided that the brokerage house meets the
               requirements set forth herein, nothing shall limit Manufacturer's
               right to select the brokerage house of its choice.

          3.3  Removal of Legends. Any legend endorsed on a certificate
               evidencing the Shares shall be removed, and Geron shall issue a
               certificate without such legend to the Manufacturer, if such
               Shares are being sold pursuant to an effective registration
               statement under the Act or pursuant to Rule 144 promulgated
               thereunder, and the purchaser of registered Shares may
               immediately resell such Shares without restriction; provided,
               however, that in the case of a sale pursuant to Rule 144, such
               holder of Shares shall provide such information as is reasonably
               requested by Geron to ensure that such Shares may be sold in
               reliance on Rule 144.

     4.   REGISTRATION RIGHTS

          4.1  Geron agrees to make commercially reasonable efforts to file with
               the Securities and Exchange Commission (the "Commission"), within
               five (5) business days after the Closing Date, a registration
               statement under the Act (the "Registration Statement"), on Form
               S-3 or other appropriate form, so as to permit a non-underwritten
               public offering and resale of the Shares under the Act by
               Manufacturer. Geron will exercise reasonable efforts to cause the
               form of the Registration Statement to satisfy all applicable
               requirements of the Act and the regulations of the Commission
               thereunder. Geron agrees to diligently pursue making the
               Registration Statement effective. Geron will notify Manufacturer
               of the effectiveness of the Registration Statement within one (1)
               business day of receiving notice from the Commission.

          4.2  Geron will maintain the Registration Statement and any
               post-effective amendment thereto filed under this Section 4
               effective under the Act until the earliest of (i) the date that
               none of the Shares covered by such Registration Statement are
               issued and outstanding, (ii) the date that all of the Shares have
               been sold pursuant to such Registration Statement, (iii) the date
               Manufacturer receives an opinion of counsel from Geron, which

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               counsel shall be reasonably acceptable to Manufacturer, that the
               Shares may be sold under the provisions of Rule 144, (iv) the
               date that all Shares have been otherwise transferred to persons
               who may trade such shares without restriction under the Act, and
               Geron has delivered a new certificate or other evidence of
               ownership for such securities not bearing a restrictive legend,
               or (v) the date all Shares may be sold at any time, without
               volume or manner of sale limitations pursuant to Rule 144(k) or
               any similar provision then in effect under the Act in the opinion
               of counsel to Geron, which counsel shall be reasonably acceptable
               to Manufacturer.

          4.3  Geron, at its expense, shall furnish to Manufacturer with respect
               to the Shares registered under the Registration Statement such
               reasonable number of copies of the Registration Statement,
               prospectuses and preliminary prospectuses in conformity with the
               requirements of the Act and such other documents as Manufacturer
               may reasonably request, in order to facilitate the public sale or
               other disposition of all or any of the Shares by Manufacturer,
               provided, however, that the obligation of Geron to deliver copies
               of prospectuses or preliminary prospectuses to Manufacturer shall
               be subject to the receipt by Geron of reasonable assurances from
               Manufacturer that Manufacturer will comply with the applicable
               provisions of the Act and of such other securities or blue sky
               laws as may be applicable in connection with any use of such
               prospectuses or preliminary prospectuses.

          4.4  All fees, disbursements and out-of-pocket expenses and costs
               incurred by Geron in connection with the preparation and filing
               of the Registration Statement under Section 4.1 and in complying
               with applicable securities and Blue Sky laws (including, without
               limitation, all attorneys' fees of Geron) shall be borne by
               Geron. Manufacturer shall bear the cost of fees and expenses of
               Manufacturer's counsel.

          4.5  Geron will advise Manufacturer promptly after it shall receive
               notice or obtain knowledge of the issuance of any stop order by
               the Commission delaying or suspending the effectiveness of the
               Registration Statement or of the initiation of any proceeding for
               that purpose, and Geron will use its commercially reasonable
               efforts to prevent the issuance of any stop order or to obtain
               its withdrawal at the earliest possible moment if such stop order
               should be issued.

          4.6  With a view to making available to Manufacturer the benefits of
               Rule 144 (or its successor rule) and any other rule or regulation
               of the Commission that may at the time permit Manufacturer to
               sell the Shares to the public without registration, Geron
               covenants and agrees to: (i) make and keep public information
               available, as those terms are understood and defined in Rule 144,
               until the earliest of (A) such date as all of the Shares may be
               resold pursuant to Rule 144(k) or any other rule of similar
               effect or (B) such date as all of the Shares shall have been
               resold; and (ii) file with the Commission in a timely manner all
               reports and other documents required of Geron under the Act and
               under the Securities Exchange Act of 1934 (the "Exchange Act"),
               as amended.

          4.7  Manufacturer will cooperate with Geron in all respects in
               connection with this Agreement, including timely supplying all
               information reasonably requested by Geron (which shall include
               all information regarding Manufacturer and proposed manner of
               sale of the Shares required to be disclosed in any Registration
               Statement) and executing and returning all documents reasonably
               requested in connection with the registration and sale of the
               Shares and entering into and performing their obligations under
               any underwriting agreement, if the offering is an underwritten
               offering, in usual and customary form, with the managing
               underwriter or underwriters of such underwritten offering.
               Nothing in this Agreement shall obligate Manufacturer to consent
               to be named as an underwriter in any Registration Statement.

          4.8  Geron shall prepare and file with the SEC such amendments and
               supplements to the Registration Statement as may be necessary to
               comply with the provisions of the Act with respect to the
               disposition of all Shares covered by the Registration Statement;
               provided, however, that promptly after filing a registration
               statement or any amendments or supplements thereto, or comparable
               statements under securities or blue sky laws of any jurisdiction,
               Geron will furnish one (1) copy to counsel designated by
               Manufacturer.

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               Geron shall promptly notify Manufacturer, at any time when the
               prospectus included in or relating to the Registration Statement
               (the "Prospectus") is required to be delivered under the Act, of
               the happening of any event as a result of which the Prospectus
               contains an untrue statement of a material fact or omits any fact
               necessary to make the statements therein, in light of the
               circumstances under which they were made, not misleading; and,
               thereafter, Geron will as promptly as possible prepare (and, when
               completed, give notice to Manufacturer) a supplement or amendment
               to such Prospectus so that, as thereafter delivered to the
               purchasers of such Shares pursuant to the Registration Statement,
               such Prospectus will not contain an untrue statement of a
               material fact or omit to state any fact necessary to make the
               statements therein, in light of the circumstances under which
               they were made, not misleading; provided that upon such
               notification by Geron of the foregoing and instructing
               Manufacturer to cease to offer and sell Shares, Manufacturer will
               its best efforts to promptly suspend its offer and sale of Shares
               until Geron has notified Manufacturer that it has prepared a
               supplement or amendment to such Prospectus and delivered copies
               of such supplement or amendment to Manufacturer.

     5.   INDEMNIFICATION.

          5.1  Geron agrees to indemnify and hold harmless Manufacturer (and
               each person, if any, who controls Manufacturer within the meaning
               of Section 15 of the Act, and each officer and director of
               Manufacturer) against any and all losses, claims, damages or
               liabilities (or actions or proceedings in respect thereof), joint
               or several, directly or indirectly based upon or arising out of
               (i) any untrue statement or alleged untrue statement of any
               material fact contained in the Registration Statement, any
               preliminary prospectus, final prospectus or summary prospectus
               contained therein or used in connection with the offering of the
               Shares, or any amendment or supplement thereto, or (ii) any
               omission or alleged omission to state a material fact required to
               be stated therein or necessary to make the statements therein not
               misleading; and Geron will reimburse each such indemnified party
               for any legal or any other expenses reasonably incurred by them
               in connection with investigating, preparing, pursuing or
               defending any such loss, claim, damage, liability, action or
               proceeding, except insofar as any such loss, claim, damage,
               liability, action, proceeding or expense (A) arises out of or is
               based upon an untrue statement or alleged untrue statement or
               omission or alleged omission made in the Registration Statement,
               any such preliminary prospectus, final prospectus, summary
               prospectus, amendment or supplement in reliance upon and in
               conformity with written information furnished to Geron by
               Manufacturer or such other person expressly for use in the
               preparation thereof, (B) the failure of Manufacturer to comply
               with its covenants and agreements contained in Sections 7.1 or
               7.5.2 hereof or (C) any misstatement or omission in any
               prospectus that is corrected in any subsequent prospectus that
               was delivered to Manufacturer prior to the pertinent sale or
               sales by Manufacturer. Such indemnity shall remain in full force
               and effect, regardless of any investigation made by such
               indemnified party and shall survive the transfer of the Shares by
               Manufacturer.

          5.2  Manufacturer agrees to indemnify and hold harmless Geron (and
               each person, if any, who controls Geron within the meaning of
               Section 15 of the Act, each officer of Geron who signs the
               Registration Statement and each director of Geron) from and
               against losses, claims, damages or liabilities (or actions or
               proceedings in respect thereof), joint or several, directly or
               indirectly based upon or arising out of, (i) any failure of
               Manufacturer to comply with the covenants and agreements
               contained in Sections 7.1 and 7.5.2 hereof or (ii) any untrue
               statement of a material fact contained in the Registration
               Statement or any omission of a material fact required to be
               stated in the Registration Statement or necessary in order to
               make the statements in the Registration Statement not misleading
               if such untrue statement or omission was made in reliance upon
               and in conformity with written information furnished to Geron by
               or on behalf of Manufacturer specifically for use in preparation
               of the Registration Statement; provided, however, that
               Manufacturer shall not be liable in any such case for (A) any
               untrue statement or omission in the Registration Statement,
               prospectus, or other such document which statement is corrected
               by Manufacturer and delivered to Geron prior to the sale from
               which such loss occurred, (B) any untrue statement or omission in
               any prospectus which is corrected by Manufacturer in any
               subsequent prospectus, or supplement or amendment thereto, and
               delivered to Geron prior to the sale or sales from which a loss
               or liability arose, or (C) any failure by Geron to fulfill any of
               its obligations under Section 5.1 hereof.

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          5.3  Promptly after receipt by any indemnified person of a notice of a
               claim or the beginning of any action in respect of which
               indemnity is to be sought against an indemnifying person pursuant
               to this Section 5, such indemnified person shall notify the
               indemnifying person in writing of such claim or of the
               commencement of such action, but the omission to so notify the
               indemnifying party will not relieve it from any liability which
               it may have to any indemnified party under this Section 5 (except
               to the extent that such omission materially and adversely affects
               the indemnifying party's ability to defend such action) or from
               any liability otherwise than under this Section 5. Subject to the
               provisions hereinafter stated, in case any such action shall be
               brought against an indemnified person, the indemnifying person
               shall be entitled to participate therein, and, to the extent that
               it shall elect by written notice delivered to the indemnified
               party promptly after receiving the aforesaid notice from such
               indemnified party, shall be entitled to assume the defense
               thereof, with counsel reasonably satisfactory to such indemnified
               person. After notice from the indemnifying person to such
               indemnified person of its election to assume the defense thereof,
               such indemnifying person shall not be liable to such indemnified
               person for any legal expense subsequently incurred by such
               indemnified person in connection with the defense thereof,
               provided, however, that if there exists or shall exist a conflict
               of interest that would make inappropriate, in the reasonable
               opinion of counsel to the indemnified person, for the same
               counsel to represent both the indemnified person and such
               indemnifying person or any affiliate or associate thereof, the
               indemnified person shall be entitled to retain its own counsel at
               the expense of such indemnifying person; provided, however, that
               no indemnifying person shall be responsible for the fees and
               expenses of more than one separate counsel (together with
               appropriate local counsel) for all indemnified parties. In no
               event shall any indemnifying person be liable in respect to any
               amounts paid in settlement of any action unless the indemnifying
               person shall have approved the terms of such settlement. No
               indemnifying person shall, without the prior written consent of
               the indemnified person, effect any settlement of any pending or
               threatened proceeding in respect of which any indemnified person
               is or could have been a party and indemnification could have been
               sought hereunder by such indemnified person, unless such
               settlement includes an unconditional release of such indemnified
               person from all liability on claims that are the subject matter
               of such proceeding.

          5.3  The provisions of this Section 5 shall survive the termination of
               this Agreement.

     6.   REPRESENTATIONS AND COVENANTS OF GERON.

          Geron hereby represents, warrants and covenants to Manufacturer as
          follows:

          6.1  Organization, Good Standing and Qualification. Geron is a
               corporation duly organized, validly existing and in good standing
               under the laws of the State of Delaware and has all requisite
               corporate power and authority to carry on its business as now
               conducted and as presently proposed to be conducted. Geron is
               duly qualified to transact business and is in good standing as a
               foreign corporation in each jurisdiction in which the failure to
               so qualify would have a material adverse effect on its business
               or properties.

          6.2  Authorization. All corporate action on the part of Geron, its
               officers, directors and stockholders necessary for the
               authorization, execution and delivery of this Agreement, the
               performance of all obligations of Geron hereunder and the
               authorization, issuance and delivery of the Shares has been taken
               or will be taken prior to the Closing, and this Agreement, when
               executed and delivered, will constitute the valid and legally
               binding obligations of Geron, enforceable against Geron in
               accordance with its terms, except as limited by applicable
               bankruptcy, insolvency, reorganization, moratorium, fraudulent
               conveyance and other laws of general application affecting
               enforcement of creditors' rights generally, as limited by laws
               relating to the availability of specific performance, injunctive
               relief or other equitable remedies.

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          6.3  Valid Issuance of Common Stock. The Shares, when issued, sold and
               delivered in accordance with the terms hereof for the
               consideration expressed herein, will be duly and validly
               authorized and issued, fully paid and nonassessable and free of
               restrictions on transfer other than restrictions on transfer
               under this Agreement and applicable state and federal securities
               laws.

          6.4  Legal Proceedings and Orders. There is no action, suit,
               proceeding or investigation pending or threatened against Geron
               that questions the validity of this Agreement or the right of
               Geron to enter into this Agreement or to consummate the
               transactions contemplated hereby, nor is Geron aware of any basis
               for any of the forgoing. Geron is neither a party to nor subject
               to the provisions of any order, writ, injunction, judgment or
               decree of any court or government agency or instrumentality that
               would affect the ability of Geron to enter into this Agreement or
               to consummate the transactions contemplated hereby.

     7.   REPRESENTATIONS AND ACKNOWLEDGMENTS OF MANUFACTURER.

          Manufacturer hereby represents, warrants, acknowledges and agrees
          that:

          7.1  Investment. Manufacturer is acquiring the Shares for
               Manufacturer's own account, and not directly or indirectly for
               the account of any other person. Manufacturer is acquiring the
               Shares for investment and not with a view to distribution or
               resale thereof, except in compliance with the Act and any
               applicable state law regulating securities.

          7.2  Access to Information. Manufacturer has consulted with its own
               attorney, accountant, or investment advisor as Manufacturer has
               deemed advisable with respect to the investment and has
               determined its suitability for Manufacturer. Manufacturer has had
               the opportunity to ask questions of, and to receive answers from,
               appropriate executive officers of Geron with respect to the terms
               and conditions of the transactions contemplated hereby and with
               respect to the business, affairs, financial condition and results
               of operations of Geron. Manufacturer has had access to such
               financial and other information as is necessary in order for
               Manufacturer to make a fully informed decision as to investment
               in Geron, and has had the opportunity to obtain any additional
               information necessary to verify any of such information to which
               Manufacturer has had access. Manufacturer acknowledges that
               neither Geron nor any of its officers, directors, employees,
               agents, representatives, or advisors has made any representation
               or warranty other than those specifically expressed herein.

          7.3  Business and Financial Expertise. Manufacturer further represents
               and warrants that it has such business or financial expertise as
               to be able to evaluate its investment in Geron and purchase of
               the Shares.

          7.4  Speculative Investment. Manufacturer acknowledges that the
               investment in Geron represented by the Shares is highly
               speculative in nature and is subject to a high degree of risk of
               loss in whole or in part; the amount of such investment is within
               Manufacturer's risk capital means and is not so great in relation
               to Manufacturer's total financial resources as would jeopardize
               the personal financial needs of Manufacturer in the event such
               investment were lost in whole or in part.

          7.5  Unregistered Securities. Manufacturer acknowledges that:

               7.5.1 Manufacturer must bear the economic risk of investment for
                    an indefinite period of time because the Shares have not
                    been registered under the Act and therefore cannot and will
                    not be sold unless they are subsequently registered under
                    the Act or an exemption from such registration is available.
                    Geron has made no agreements, covenants or undertakings
                    whatsoever to register any of the Shares under the Act,
                    except as provided in Section 4 above. Geron has made no
                    representations, warranties or covenants whatsoever as to
                    whether any exemption from the Act, including, without
                    limitation, any exemption for limited sales in routine
                    brokers' transactions pursuant to Rule 144 under the Act,
                    will become available and any such exemption pursuant to
                    Rule 144, if available at all, will not be available unless:
                    (i) a public trading market then exists in Geron's common
                    stock, (ii) Geron has complied with the information
                    requirements of Rule 144, and (iii) all other terms and
                    conditions of Rule 144 have been satisfied.

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               7.5.2 Transfer of the Shares has not been registered or qualified
                    under any applicable state law regulating securities and,
                    therefore, the Shares cannot and will not be sold unless
                    they are subsequently registered or qualified under any such
                    act or an exemption therefrom is available. Geron has made
                    no agreements, covenants or undertakings whatsoever to
                    register or qualify any of the Shares under any such act
                    except as provided in Section 4 above. Geron has made no
                    representations, warranties or covenants whatsoever as to
                    whether any exemption from any such act will become
                    available.

               7.5.3 Manufacturer hereby certifies that it is an "Accredited
                    Investor" as that term is defined in Rule 501 under the Act.

     8.   TAX ADVICE. Manufacturer acknowledges that Manufacturer has not relied
          and will not rely upon Geron or Geron's counsel with respect to any
          tax consequences related to the ownership, purchase, or disposition of
          the Shares. Manufacturer assumes full responsibility for all such
          consequences and for the preparation and filing of all tax returns and
          elections which may or must be filed in connection with the Shares.

     9.   NOTICES. Any notice, demand or other communication required or
          permitted hereunder shall be in writing and shall be deemed to have
          been duly given on the date of delivery if delivered personally or by
          facsimile, or one day, not including Saturdays, Sundays, or national
          holidays, after sending if sent by national overnight delivery
          service, or five days, not including Saturdays, Sundays, or national
          holidays, after mailing if mailed by first class United States mail,
          certified or registered with return receipt requested, postage
          prepaid, and addressed as follows:

                  To Geron at:          Geron Corporation
                                        230 Constitution Drive
                                        Menlo Park, California  94025
                                        Attention: General Counsel
                                        Telephone:        (650) 473-7700
                                        Facsimile:        (650) 473-7750

                  To Manufacturer at:   Girindus America Inc.
                                        8560 Reading Rd
                                        Cincinnati , Ohio, 45215
                                        Attention: President
                                        Telephone:        (513) 679 - 3000
                                        Facsimile:        (513) 679 - 3053

     10.  BINDING EFFECT. This Agreement shall be binding upon the heirs, legal
          representatives and successors of Geron and of Manufacturer; provided,
          however, that Manufacturer may not assign any rights or obligations
          under this Agreement except to an entity controlling, under common
          control with or controlled by Manufacturer. Geron may not assign any
          of its rights or obligations under this Agreement.

     11.  GOVERNING LAW. This Agreement shall be governed by and construed in
          accordance with the laws of the State of Delaware.

     12.  INVALID PROVISIONS. In the event that any provision of this Agreement
          is found to be invalid or otherwise unenforceable by a court or other
          tribunal of competent jurisdiction, such invalidity or
          unenforceability shall not be construed as rendering any other
          provision contained herein invalid or unenforceable, and all such
          other provisions shall be given full force and effect to the same
          extent as though the invalid and unenforceable provision was not
          contained herein.

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

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     14.  AMENDMENTS. This Agreement or any provision hereof may be changed,
          waived, or terminated only by a statement in writing signed by the
          party against whom such change, waiver or termination is sought to be
          enforced.

     15.  FUTURE COOPERATION. Each of the parties hereto agrees to cooperate at
          all times from and after the date hereof with respect to all of the
          matters described herein, and to execute such further assignments,
          releases, assumptions, amendments of the Agreement, notifications and
          other documents as may be reasonably requested for the purpose of
          giving effect to, or evidencing or giving notice of, the transactions
          contemplated by this Agreement.

     16.  ENTIRE AGREEMENT. This Agreement and the Supply Agreement, including
          Project Order No. 1 thereto, constitute the entire agreement of the
          parties pertaining to the Shares and supersede all prior and
          contemporaneous agreements, representations, and understandings of the
          parties with respect thereto.




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     IN WITNESS WHEREOF, the parties hereto have executed this Common Stock
Purchase Agreement as of the date first above written.


                                        Geron Corporation


                                        /s/ David L. Greenwood
                                        ----------------------------------------
                                        By:     David L. Greenwood
                                        Title:  Executive Vice President and
                                                Chief Financial Officer

                                        Girindus America Inc.


                                        /s/ Greg McParland
                                        ----------------------------------------
                                        By:     Greg McParland
                                        Title:  CEO