Many evidence support the notion that p63 has tumor suppressor functions: 1) p63 specific siRNA enhances the transformation potential of p53−/− MEFs [38]; 2) p63 can mediate chemo-sensitivity independent of p53 status by induction of apoptosis [17], [39]; 3) The combined absence of p63 and p73 severely impairs the induction of p53-dependent apoptosis in response to DNA damage [40]. This evidence concerns the gene TP53 and neoplasm.