MDM2 and cancer: Activated wild-type p53 may bind to the specific DNA regions of its target genes (p21, Wip1, Noxa, and PUMA), thus mediating tumor suppressor function [26]; whereas mutated p53 in the conformation-sensitive core domain is accumulated in the cancer cells due to the inhibition of MDM2 activity by the Hsp90 complex, towards mutated p53 [27].