Cyclin-dependent kinases (CDKs) are key regulators of cell cycle progression and are therefore promising targets for cancer therapy. BMS-265246 is a cell-permeable inhibitor of Cdk1/cyclin B and Cdk2/cyclin E (IC50s = 6 and 9 nM, respectively). It less potently inhibits Cdk4/cyclin D (IC50 = 0.23 μM). BMS-265246 blocks the cycling of HCT-116 cells (EC50 = 0.29-0.49 μM), resulting in cell cycle arrest in G2 phase.