<prompt> Which of the following is not a cycling dependant kinase CRK inhibitorP21P27P53P57  <response>: Ref Robbins illustrated 7e p292, ref Robbins 8e p286; 9e p25_26 CyclinD form complex with cyclin dependant kinases and regulate the transition of cell cycle from one stage to other. These CDK complexes in turn are regulated by CDK inhibitor .the inhibitor controls the cell cycle by balancing the activity of CDKs .this signals from these inhibitors determine whether a cell professes through the cell cycle Changes in the level of these inhibitors may occur in some tumors or possibly in aging cells The cyclin dependant kinnase inhibitors are P21,p27,p57,p15,p16,p18p,19 