PTCH1 (patched 1) functions as a receptor for sonic, indian, and desert hedgehog proteins, associating with smoothened (SMO) to transduce hedgehog signaling 1. The protein acts as a tumor suppressor, with inactivation serving as a critical step in tumorigenesis. PTCH1 mutations are responsible for nevoid basal cell carcinoma syndrome (NBCCS), characterized by multiple basal cell carcinomas and keratocystic odontogenic tumors 2. Germline mutations cause autosomal dominant NBCCS, while somatic mutations occur frequently in sporadic keratocystic odontogenic tumors, with mutations predominantly clustered in extracellular and intracellular loop domains 34. Tumorigenesis involves a two-hit mechanism combining transcriptional silencing and mutational inactivation of PTCH1 alleles 5. Beyond cancer, PTCH1 variants associate with reduced spine bone mineral density and osteoporotic fracture risk 6, and polymorphisms in the gene confer susceptibility to chr9 obstructive pulmonary disease, reflecting PTCH1's role in lung morphogenesis 7. These findings establish PTCH1 as a pleiotropic gene critical for hedgehog signaling, skeletal homeostasis, and pulmonary development.