A 2-aminothiazole-derived, small-molecule cyclin dependent kinase (CDK) inhibitor with potential antineoplastic activity. CDK inhibitor SNS-032 selectively binds to CDKs 2, 7, and 9, preventing their phosphorylation and activation; inhibition of CDK activity may result in cell cycle arrest, the induction of apoptosis and decreased tumor cell proliferation in susceptible tumor cell populations. This agent has been shown to sensitize radioresistant tumor cells to ionizing radiation.