CTAG2 encodes an autoimmunogenic tumor antigen that belongs to the ESO/LAGE family of cancer-testis antigens. This protein is expressed in a wide array of cancers including melanoma, breast cancer, bladder cancer and prostate cancer. This protein is also expressed in normal testis tissue. An alternative open reading frame product of CTAG2 has been described in PMID: 10399963. This alternate protein, termed CAMEL, is a tumor antigen that is recognized by melanoma-specific cytotoxic T-lymphocytes. Alternate splicing results in multiple transcript variants.