PTCH1 and neoplasm: OKCs are presently classified as tumour-like cystic lesions, but in the previous edition of the WHO classification, they were among the tumours, as keratocystic odontogenic tumours, on the basis of the common mutation identified in the Patched-1 gene of the sonic hedgehog pathway, a key event in the development of the nevoid basal cell carcinoma syndrome, the Gorlin-Goltz syndrome [3, 4].