Early mechanism-of-action studies suggested that PTC596 induces binding of CDK1 to BMI-1 and CDK1-mediated phosphorylation of BMI-1 at two novel N-terminal sites, leading to degradation of BMI-1.28 In this study, we investigated preclinical in vitro and in vivo activities of PTC596 and the mechanisms of action in AML, having special attention to p53-dependency in inducing apoptosis. Here, TP53 is linked to acute myeloid leukemia.