TP53 and cancer: Therefore, a number of small molecule inhibitors of the Mdm2–p53 PPI that stabilize p53 and induce apoptosis have been developed as anticancer agents, several of which progressed to clinical trials (Fig. 3B).32,122–125 Additionally, several small molecule re-activators of p53 variants mutated in cancers have been developed and tested in clinical trials.122,126 Finally, an alternative strategy for p53 stabilization via inhibition of the p53 deubiquitinating enzyme, USP7, has been also explored.127