Tyrosinase (TYR) is an enzyme that catalyzes steps in the conversion of tyrosine to melanin. Mutations in TYR results in oculocutaneous albinism, and polymorphisms results in variations in skin pigmentation. The protein is found in melanocytes in the skin and retina, and is useful to identify melanocytic neoplasms such as melanomas. It is also found in subsets of renal angiomyolipomas and PEComas. References: PNAS USA 1995 92:8125; Arch Path Lab Med 2007 131(1):122; Arch Path Lab Med 2009 133:648