SLC45A2 is a melanocyte differentiation antigen that is expressed in a high percentage of melanoma cell lines. A similar sequence gene in medaka, 'B,' encodes a transporter that mediates melanin synthesis. Mutations in this gene are a cause of oculocutaneous albinism type 4.The protein encoded by this gene encodes a melanocyte differentiation antigen that is expressed in a high percentage of melanoma cell lines. A similar sequence gene in medaka, 'B,' encodes a transporter that mediates melanin synthesis. Mutations in this gene are a cause of oculocutaneous albinism type 4. Alternative splicing results in multiple transcript variants encoding different isoforms.