PTCH1 is a member of the patched gene family. The protein is the receptor for sonic hedgehog, a secreted molecule implicated in the formation of embryonic structures and in tumorigenesis. It functions as a tumor suppressor. Mutations of its gene have been associated with nevoid basal cell carcinoma syndrome, esophageal squamous cell carcinoma, trichoepitheliomas, transitional cell carcinomas of the bladder, as well as holoprosencephaly.