Melanoma-associated antigen 3, also known MAGEA3, is a member of the MAGE gene family, which comprises 12 known genes, of which 6 are expressed in tumors. The MAGE genes were initially isolated from different kinds of tumors, and based on their virtually exclusive tumor-specific expression in adult tissues, they have been used as targets for cancer immunotherapy. MAGEA3 is a tumor-specific antigen widely expressed in solid and hematologic malignancies, but not in normal tissues, with the exception of testis and placenta. Therefore, MAGEA3 is an excellent candidate tumor antigen.