Antibodies are available for the investigation of MART1, also known as Melan-A or melanoma antigen recognized by T cells 1. It is a human protein encoded by MLANA, 118 amino acids in length and with a reported mass of 18 kDa. It is a cell surface protein antigen expressed on the melanocytes, first discovered in melanoma cells. It is now a well known marker for melanocytic tumors. MART1 shares homology with mouse, rat, and frog.