Exhibit 4
                                    ---------

                           EMMET, MARVIN & MARTIN, LLP

                               COUNSELLORS AT LAW



                                                                
                                                                 177 MADISON AVENUE
                                 120 BROADWAY               MORRISTOWN, NEW JERSEY 07960
                                                                   (973) 538-5600
WRITER'S DIRECT DIAL       NEW YORK, NEW YORK 10271              FAX: (973) 538-6448
                                    _____
                                                              1351 WASHINGTON BOULEVARD
                                (212) 238-3000                        2ND FLOOR
                                    _____                 STAMFORD, CONNECTICUT 06902-4543
                                                                   (203) 425-1400
                             FAX: (212) 238-3100                 FAX: (203) 425-1410
                          http://www.emmetmarvin.com


                                  May 19, 2004

The Bank of New York
  as Depositary
101 Barclay Street
New York, New York, 10286

Re:   American Depositary Receipts for Common Shares, Par Value GBP 1 each, of
      GeneMedix Plc
      --------------------------------------------------------------------------

Ladies and Gentlemen:

      We refer to the  registration  statement to be filed on Form F-6 under the
Securities  Act of 1933  (the  "Registration  Statement")  by the  legal  entity
created by the  agreement  (the  "Deposit  Agreement")  for issuance of American
Depositary Shares ("ADSs")  evidenced by American  Depositary  Receipts ("ADRs")
for common shares,  par value GBP 1 each, of GeneMedix Plc for which you propose
to act as Depositary.

      We are of the opinion that the ADSs covered by the Registration Statement,
when issued in accordance  with the terms of the Deposit  Agreement,  will, when
sold,  be legally  issued and will  entitle  the  holders  thereof to the rights
specified in the Deposit Agreement and the ADRs.

      This  opinion  may  be  used  by  you as an  exhibit  to the  Registration
Statement.

                                                  Very truly yours,

                                                  /s/EMMET, MARVIN & MARTIN, LLP
                                                  ------------------------------
                                                  EMMET, MARVIN & MARTIN, LLP