TYRP1 and melanoma: TYRP1 is specifically expressed in melanocytes and melanoma cells.[28] Also referred to as 5,6-dihydroxyindole-2-carboxylate oxidase or gp75 glycoprotein in some studies, it acts as a key enzyme in melanin biosynthesis: it catalyzes the oxidation of tyrosine to 5,6-dihydroxyindole-2-carboxylic acid – a critical intermediate in the pathway – thereby promoting melanin synthesis.[29,30] As a natural pigment, melanin is essential for skin, hair, and eye pigmentation; TYRP1 enzymatic activity regulates melanin production, thus influencing tissue pigmentation.