It has been reported that multiple HFSC populations readily develop BCC-like tumours in Ptch1-deleted mice, and targeting Shh signalling pathway components, such as using smoothened inhibitors (e.g., vismodegib (Erivedge®) and sonidegib (Odomzo®), can treat BCC [88, 252]. This evidence concerns the gene PTCH1 and skin basal cell carcinoma.