CDKN2A and carcinoma: As proof of principle that the loss of p16ink4a/p19arf can contribute to ΔNp63α-induced malignant conversion, an in vivo grafting study showed that, similar to lenti-ΔNp63α-expressing keratinocytes, p19arf null keratinocytes formed malignant carcinomas in the presence of v-rasHa (Figure 7).