MDM2 and cancer: On the other hand, Wiech et al. [97] observe that HSP70, whose levels are commonly high in cancers, accelerates CHIP-mediated degradation of mutp53 (R175H), whereas HSP70 partially inhibits MDM2-mediated ubiquitination and degradation of exogenous mutp53 (V143A, R175H) to enhance formation of nuclear aggregates.