Background of the antigen
A family of proteins designated as cdks are critical regulators of cell cycle progression. The prototype member of this family, p34 / Cdc 2, and a related protein Cdk 2, function late in the cycle, while Cdk 4 and Cdk 6 are critically involved in G 1 to S progression. The cyclin partner of p36 / Cdk 3 is not yet identified.