MCL1 and leukemia: ➢Inhibitor of CDK1, 2, 5 and 9 with IC50 of 3 nM, 1 nM, 1 nM, and 4 nM, respectively.➢Blocks thymidine DNA incorporation (IC50: 4 nM) and suppressed retinoblastoma phosphorylation, which correlated with induction of apoptosis.➢Induces cell-cycle arrest in more than 100 tumor cell lines.➢Broad antiproliferative activity, downregulates expression of MCL-1 and induces apoptosis in in vitro and in vivo models of leukemia, significantly prolonged survival in vivo.➢Evaluated in clinical trials, alone or in combination, in various hematologic indications, with varied efficacy and side effects.