EXHIBIT 32.2


                            CERTIFICATION PURSUANT TO
                            18 U. S. C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-0XLEY ACT OF 2002


In connection with the Quarterly Report of GTx, Inc. (the "Company") on Form
10-Q for the period ended September 30, 2004, as filed with the Securities and
Exchange Commission on the date hereof (the "Report"), I, Mark E. Mosteller,
Chief Financial 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:

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

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





/s/ MARK E. MOSTELLER, CPA
- -------------------------------------------
Mark E. Mosteller, CPA
Chief Financial Officer

November 12, 2004