Roscovitine is a potent and selective CDK inhibitor for Cdc2, CDK2 and CDK5 with IC50 of 0.65 μM, 0.7 μM and 0.16 μM and shows little effect on CDK4/6.

PHA-767491 HCl is a potent and ATP-competitive cyclin-dependent kinase (cdk) inhibitor with IC50 values of 10/34 nM for Cdc7/Cdk9.

Purvalanol A is a selective inhibitor of cyclin-dependent kinases (CDKs), it potently inhibits cdc2/cyclin B, Cdk2/cyclin A, Cdk2/cyclin E, Cdk4/cyclin D1 and Cdk5-p35 with IC50 values of 4, 70, 35, 850, and 75 nM respectively.

XL413 HCl is a potent and selective Cdc7 inhibitor with an IC50 of 3.7 nM, > 60-fold selectivity against CK2, > 10-fold selectivity against PIM, and > 300-fold selectivity against a panel of over 100 protein kinases.