Plays a role in neuronal proliferation and differentiation. Plays a role in the accumulation of cellular cholesterol. Involved in intracellular lipid droplet formation. May contribute to cholesterol homeostasis in neuronal cells. Predominantly localized to cholesterol-enriched domains within the membrane (By similarity). Localizes to cytoplasmic punctate vesicular structures (By similarity). Expressed in brain, retina, testis and thymus (PubMed:19179482). Down-regulated by thyroid hormone T3 (PubMed:19179482). The SSD (sterol-sensing) domain is necessary for the increase in cellular cholesterol uptake. Belongs to the patched family.