June 28, 2404 Dr. Elia Napolitano elia.napolitano@de.ey.com Phone:+49 (89) 14331 - 13106 Fax; +49 (89) 14331 - 17113 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the: 2002 Incentive Stock Option Plan 2001 Incentive Stock Option Plan 2000 Incentive Stock Option Plan 1999 U.S. Incentive Stock Option Plan 1996 Mitotix, Inc. Equity Incentive Plan Convertible Bonds Terms and Conditions for Managers of the Company and Management Bodies and Second-Tier Domestic and Management of Foreign Affiliated Enterprises as well as for Consultants dated May 21, 2003 Convertible Bonds Terms and Conditions for Managers of the Company and Management Bodies and Management of Second-Tier Domestic Foreign Affiliated Enterprises as well as for Consultants dated June 11, 2002 of GPC Biotech AG of our report dated March 4, 2004, except for Note 3, as to which the date is June 7, 2004, with respect to the consolidated financial statements of GPC Biotech AG included in its Registration Statement (Form F-1 333-116303), filed with the Securities and Exchange Commission. Ernst & Young AG Wirtschaftsprufungsgeselleschaft /s/ Dr. Elia Napolitano /s/ Dirk Gallowsky - -------------------------- ------------------------- Dr. Elia Napolitano ppa. Dirk Gallowsky