MDM4 and neoplasm: Indeed, nutlin-3, an MDM2 inhibitor which restores p53 function in tumor cells that retain a wild-type p53, cooperate with several HDACis (including NaB) to induce cell death in p53 wild-type tumor cell lines but not in p53-null PC-3 prostatic carcinoma likely by HDACi-induced p53 hyperacetylation and/or MDM2/MDM4 downregulation [52].