Binds cholesterol. Colocalizes with PROM1 (By similarity). Associates with membrane in a cholesterol-dependent manner. Localizes to the apical and basolateral membranes of epithelial cells. Expressed in kidney and testis. Present in urine within small membrane particles (at protein level). In the submandibular gland, expressed in seromucous acini. In the parotid gland, expressed in the serous acini and in all segments of the duct system. In the sublingual gland, expressed in large excretory ducts, but absent in intercalated ducts. In the extraorbital lacrimal gland, expressed in the serous acini. In the eyelid, expressed in the acini of the meibomian gland. Glycosylated. Belongs to the prominin family.