Previous studies showed that in contrast to the corresponding natural mouse peptide gp10025-33 (EGSRNQDWL), the human orthologue CTL epitope gp10025-33 (KVPRNQDWL, KVP) induced 'self '-reactive CTL responses. The modified peptide EGP (EGPRNQDWL) result in strong in vivo immunogenicity combined with increased binding affinity and strong stabilization of H-2Db, generating a very potent peptide vaccine.