EXHIBIT 32.1

     CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT
                TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the StemCells, Inc. (the "Company") Annual Report on Form
10-K for the year ending December 31, 2001 as filed with the Securities and
Exchange Commission on the date hereof (the "Report"), I, Martin McGlynn,
President and Chief Executive Officer of the Company, certify pursuant to 18
U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, that, to the best of my knowledge:

         (1).     The Report fully complies with the requirements of Section
                  13(a) or 15(d) of the Securities Exchange Act of 1934, as
                  amended; and

         (2).     The information contained in the Report fairly presents, in
                  all material respects, the financial condition and results of
                  operations of the Company.

Date: April 5, 2004

/s/ Martin McGlynn
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Martin McGlynn
President and Chief Executive Officer