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 to cutaneous melanom, involved in the regulation of melanosome formation. MART-1 is expressed in skin and retinae melanocytes and in 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, specially 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 by means of several vaccination strategies.