CDK4 and mantle cell lymphoma: In conclusion, our results indicate, that combined inhibition of CYCLIN D1/CDK4/RB and CK2/PI3K/AKT via a small molecule inhibitor of the CDK4/6 and CK2 kinases is effective in inducing cell death of MCL and T-ALL, particularly those that have aberrant upregulation of both signaling pathways.