P63 is a master gene for normal epithelial stem cells, protecting them from apoptosis and coordinating their differentiation.27 P73 can transcribe endogenous p53-responsive genes such as p21,28, 29 and reporters containing various p53-responsive promoters.30 Normally, p63 and p73 are rarely mutated in tumors, but they can be inhibited by mutant p53, resulting in enhancement of oncogenic potential of the affected cell lines (Figure 3).31, 32 A comprehensive review on p63 as a tumor suppressor and its interaction with mutant p53 has been presented previously.33 Here, TP53 is linked to neoplasm.