Small molecule inhibitors of Hedgehog signalling, such as Vismodegib, which has a similar mode of action to cyclopamine, have been used successfully in the treatment of basal cell carcinomas in which Hedgehog signalling is activated by mutations in SMO or PTCH1, downstream of expression of a Hedgehog ligand (Von Hoff et al., 2009). Here, PTCH1 is linked to basal cell carcinoma.