A synthetic peptide consisting of amino acids 368 through 376 of the melanoma-associated antigen tyrosinase with an amino acid aspartic acid at position 370 to improve immunogenicity. Vaccination with TYROSINASE:368-376(370D) may stimulate the host immune system to mount a cytotoxic T lymphocyte (CTL) response against tumor cells positive for tyrosinase, thereby decreasing tumor growth. [ ]