Acts as a receptor for sonic hedgehog (SHH), indian hedgehog (IHH) and desert hedgehog (DHH). Associates with the smoothened protein (SMO) to transduce the hedgehog's proteins signal. Expression is seen in the embryonic neural tube, sclerotome, visceral mesoderm, and limb bud. In stage 10 embryo, expression is seen in neural tube, and at lower levels in the notochord, epithelial somites, endoderm and splanchnic mesoderm. At stage 18, PTC is broadly expressed in the neural tube but excluded from the cells of the floor plate. At stage 32, expression occurs in the mesodermal cells of the gastrointestinal tract. Activated by hedgehog; repressed by itself. Glycosylation is necessary for SHH binding. Belongs to the patched family.