TP53 and cancer: The p53 tumor suppressor is perhaps represents one of the most important drug targets in cancer therapy as the corresponding gene has been found to be mutated or deleted in half of all malignant tumors, whereas the other half express wild-type p53 and in one way or another is functionally blocked (Essmann and Schulze-Osthoff, 2012; Mirzayans et al., 2012).