MAGEA1 (Melanoma-associated antigen 1) is a protein that functions in transcriptional regulation and potentially embryogenesis and tumorigenesis. Members of the MAGEA family are implicated in some hereditary disorders, such as dyskeratosis congenita. MAGE was originally isolated from human melanoma cells as an antigen that is recognizes by cytolytic T lymphocytes. It has since been documented in other carcinomas. In addition, expression has been documented in highly proliferating germ cells. In immunohistochemistry, MAGEA1 has nuclear and cytoplasmic positivity in spermatogonia in seminiferous ducts in the testes. References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804;