Flavopiridol is a synthetic flavone compound that inhibits the phosphorylation of cyclin-dependent kinases (Cdks) and suppresses expression of cyclin D1 and D3, interrupting the central role of Cdks in the regulation of the cell cycle and consequently promoting apoptosis. This action has been exploited in studies investigating the suppression of oncogenic proliferation, synovial hyperplasia, and joint destruction related to rheumatoid arthritis. Flavopiridol is an inhibitor of Cdk1, Cdk10, Cdk11, Cdk2, Cdk3, Cdk4, Cdk5, Cdk6, Cdk7, Cdk8 and Cdk9.