K00546 is a potent CDK1 and CDK2 inhibitor with IC50s of 0.6 nM and 0.5 nM for CDK1/cyclin B and CDK2/cyclin A, respectively. K00546 is also a potent CDC2-like kinase 1 (CLK1) and CLK3 inhibitor with IC50s of 8.9 nM and 29.2 nM, respectively.