MDM2 and leukemia: In addition, researchers designed Proteolysis-targeting chimera (PROTAC) degraders based on MDM2 inhibitors.375 WB156, consisting of a nutlin derivative linked to the CRBN ligand lenalidomide, effectively depleted MDM2 and activated wild-type p53, thereby inducing apoptosis.376,377 The rapid degradation of MDM2 by MD-224 resulted in complete tumor regression in leukemia cells carrying wild-type p53.378