MAGEC1 is a member of the melanoma antigen gene (MAGE) family. MAGEC1 proteins of this family are tumor-specific antigens that can be recognized by autologous cytolytic T lymphocytes. MAGEC1 protein contains a large number of unique short repetitive sequences in front of the MAGE-homologous sequence, and therefore is about 800 aa longer than the other MAGE proteins.