CVT-313 is a potent, cell-permeable, selective, reversible, and ATP-competitive inhibitor of Cdk2 (IC50 = 0.5 µM for Cdk2/A and Cdk2/E; 4.2 µM for Cdk1/B; 215 µM for Cdk4/D1). Inhibits other kinases only at much higher concentrations (IC50 >1.25 mM for MAPK, PKA, and PKC).