Indeed, several other genes that are essential to maintain an epithelial barrier, such as Ikka, Pkk, Kdf1, Tp63, and Stratifin [50,51,52,53,54], have also been shown to suppress SCC formation, and the tumor phenotype elicited upon loss of these genes is much faster and widespread compared to loss of the canonical tumor suppressor gene p53 [19]. This evidence concerns the gene RIPK4 and neoplasm.