Probably, aberrant Ras signaling does not play a role in DMBA/TPA-induced BCC development in Ptchf/f CD4Cre mice [11], while the disruption of physiological apoptotic responses via the DMBA/TPA-mediated downregulation of p53 [19] is more likely [12,20,21]. Here, TP53 is linked to skin basal cell carcinoma.