TP73 and cancer: In cancers with p53 mutations, which are detected in more than 50% of human cancers [2,26,27], the inhibition of the p73 transcriptional activity on the expression of cell cycle inhibitors, including p21WAF1, and pro-apoptotic genes, such as Bax and PUMA, is an important mechanism by which cancer cells escape apoptosis and develop resistance to chemotherapy.