Given the infrequent coincident activation of RAS genes and mutational inactivation of TGFβ receptors in sporadic cSCC, we finally sought to model this disease by inactivating Tp53 function coupled with deletion of Tgfbr1 in LGR5+ve cells (Supplementary Fig. 9f). This evidence concerns the gene LGR5 and skin squamous cell carcinoma.