Cutaneous T cell lymphomas (CTCL) represent a group of malignancies that originate from CD4-T lymphocytes and manifest on the skin. CTCL is a general term for several neoplasms including mycosis fungoides, T cell leukemia/ lymphoma and pagetoid reticulosis, all of which are very difficult to treat in the advanced stages. CTAGE2 (cutaneous T cell lymphoma associated-antigen 2) is a member of the cancer/testis antigen family of proteins (CTAGE) that, under normal conditions, are found primarily in the testis with little or no expression in other parts of the body. Another member of the CTAG family, namely CTAGE5 (also known as MEA11, MEA6, MGEA11 or MGEA6), is a tumor associated antigen that is found in tumors of various origins, including cutaneous T cell lymphomas. Both CTAGE2 and CTAGE5 are expressed as multiple isoforms due to alternative splicing events.