For example, mutations in Ptch1, Smo, Gli1 and Gli3 are linked to BCC,medullablastoma and pancreatic cancer [40,42,43,46-48].Ligand upregulation can also drive cancer formation, as has been described in breast,ovarian, pancreatic, prostate and lung cancers [41,49-52]. This evidence concerns the gene SMO and skin basal cell carcinoma.