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                                                                   EXHIBIT 10.48

                                    AGREEMENT


         This Agreement is effective April 22, 1991 by and between Genzyme
Corporation having a place of business at One Kendall Square, Cambridge, MA
02139-1562 ("GENZYME") and Pharmaceutical Proteins Limited having a principal
place of business at Kings Buildings, West Mains Road, Edinburg, EH9 3JQ,
("PPL").

WHEREAS, both parties have substantial programs and interest in the development
of transgenic animals;

WHEREAS, Genzyme's Patent Application, USSN 849,815 has the basis for claims
which could impact PPL's transgenic animal program;

WHEREAS, PPL's Patent Application W088/00239 has the basis for claims which
could impact Genzyme's transgenic animal program; and

WHEREAS, both parties wish to continue their programs without threat from the
other party while still pursuing areas of interest reserved for themselves.

NOW, THEREFORE the parties agree as follows:

1.0      Definitions

         1.1      Genzyme Patent Rights shall mean USSN 849,815 and all division
                  and continuation patent applications thereof, all counterpart
                  foreign applications on the foregoing, and all patents issuing
                  thereon.

         1.2      PPL Patent Rights shall mean W088/00239 and all division and
                  continuation patent applications thereof, all counterpart
                  foreign applications on the foregoing, and all patents issuing
                  thereon.

         1.3      Genzyme Field shall mean all promoters except those
                  using betalactoglobulin .

         1.4      PPL Field shall mean all promoters except those using
                  whey-acid protein.

         1.5      Far East shall mean Japan, China, Taiwan, Thailand, India,
                  Sri Lanka, Indonesia, Philippines, Vietnam, Singapore,
                  Malaysia, Hong Kong, Myanmar (Burma), Pakistan, Bangladesh,
                  South Korea, Laos, Cambodia and their respective succession
                  states.

2.0      Grant

         2.1      Genzyme hereby grants PPL a non-exclusive, royalty-free,
                  worldwide, except for the Far East, license under Genzyme
                  Patent Rights in the PPL Field for all uses
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                  including the right to make, have made, use and sell
                  transgenic animals and proteins made thereby.

         2.2      PPL hereby grants Genzyme a non-exclusive, royalty-free
                  worldwide, except for the Far East, license under PPL Patent
                  Rights in the Genzyme Field for all uses including the right
                  to make, have made, use and sell transgenic animals and
                  proteins made thereby.

         2.3      Genzyme has granted rights in the Far East to another entity
                  who has expressed an interest in entering a like arrangement.
                  Both parties agree to facilitate such cross-licensing.

3.0      Miscellaneous

         3.1      Each party states that it has the power and authority to enter
                  into this Agreement and to grant the rights granted herein.

         3.2      The official language of this Agreement shall be the
                  English language.

         3.3      The parties agree to negotiate and attempt to settle, in good
                  faith, any disputes arising out of this Agreement. If the
                  parties are unable to come to an agreement, the dispute shall
                  be finally settled by arbitration conducted in accordance with
                  the rules of conciliation and arbitration of the International
                  Chamber of Commerce in effect on the date hereof. Any such
                  arbitration shall take place in New York City, New York,
                  U.S.A. and shall be conducted in the English language. The
                  arbitrator shall apply the laws of the State of New York. Both
                  parties shall bear their own costs. Any award by the
                  arbitrator shall be binding and conclusive upon the parties
                  and each party submits itself to the jurisdiction of the New
                  York Federal or State courts for entry of judgement with
                  respect to the decision of the arbitrator. The award may also
                  be entered in and enforceable by any other court having
                  jurisdiction over the parties.

         3.4      This Agreement represents the entire understanding between the
                  parties and supersedes all prior agreements between the
                  parties with respect to the subject matter hereof, and there
                  are no other agreements or representations, either written or
                  oral, that have not been incorporated herewith. The parties,
                  by their duly authorized signature below, signify their
                  agreement herewith.


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The parties, by their duly authorized signature below, signify their agreement
herewith.


PHARMACEUTICAL PROTEINS LIMITED                 GENZYME CORPORATION

BY:/s/       Ron James                          BY:/s/          Alan Smith
   ----------------------------------              -----------------------------


TITLE:   Managing Director                      TITLE:   Senior V.P.-Research
      -------------------------------                 --------------------------


DATE:         21-10-91                          DATE:            24-10-91
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