Plays a role in migration and segregation of pigment cells (melanophores and xanthophores). Contributes to pigment stripe patterning in the epidermis. Mainly found in the Golgi apparatus. Strongly expressed in melanophores and xanthophores. Also detected in eye, brain, heart, skin, fin, testis and ovary. N-glycosylated. Belongs to the tetraspanin (TM4SF) family.