TP53 and cancer: The function of p53 family proteins is required for normal stress-induced apoptosis (Agami et al, 1999; Gong et al, 1999; Yuan et al, 1999; Flores et al, 2002; Gressner et al, 2005; Stiewe, 2007) and they are frequently inactivated in cancer cells by mutations (p53 in particular) or alternate mechanisms.