PTCH1 and skin basal cell carcinoma: Basal cell carcinoma (BCC) represents the most common type of non-melanoma skin cancer.1-4 The main molecular pathogenetic driver of BCC is constituted by the aberrant activation of the Hedgehog (Hh) pathway, involving mutations of patched-1 (PTCH1) and smoothened (SMO) genes.5 Moreover, Gorlin syndrome (GS), resulting from PTCH1 germline mutations,6-9 is a well-established, hereditary BCC-predisposing disorder.