MART-1 (Melan-A) gene is 18 kb long and comprises five exons. It is expressed in most melanoma tumor samples, and among normal cells, only in melanocytes. In cancer immunotherapy, epitopes and variants derived from the MART-1/Melan-A protein are widely used as clinical vaccines. The epitopes spanning amino acid residues 26–35 and 27–35 from the MART-1/Melan-A protein, highly expressed in melanoma cells, provide a prime example of T cell recognition of multiple peptides and the use of peptide variants designed to elicit altered immunological responses.