MART-1 is a hydrophobic transmembrane protein without glycosylation sites highly enriched in early melanosomes. MART-1 is necessary for gp1 function, another antigen associated with cutaneous melanoma, involved in the regulation of melanosome formation. MART-1 is expressed in skin and retinae melanocytes and the majority of melanoma tumors, but it is absent from other tissues and tumors. It was isolated thanks to the specific recognition by T lymphocytes of MART-1 derived peptides, especially in the context of the HLA-A21 haplotype, present in tumor infiltrates from melanoma patients. Thus, MART-1 is immunogenic in humans and has been widely exploited to induce anti-melanoma immunity in patients through several vaccination strategies.