Protein patched homolog 1 is a protein that is the member of the patched family and in humans is encoded by the PTCH1 gene.

PTCH1 is a member of the patched gene family and is the receptor for sonic hedgehog, a secreted molecule implicated in the formation of embryonic structures and in tumorigenesis. This gene functions as a tumor suppressor. The PTCH1 gene product, is a transmembrane protein that suppresses the release of another protein called smoothened, and when sonic hedgehog binds PTCH1, smoothened is released and signals cell proliferation.