CDK6 and B-cell chronic lymphocytic leukemia: Cyclin-dependent kinase 6 (CDK6) encodes a regulator of G1/S cell-cycle progression and has been found rearranged in B-cell lymphoma (IGK/CDK6), chronic lymphocytic leukemia (IGL/CDK6, IGH/CDK6, IGK/CDK6), and acute lymphoblastic leukemia (CDK6/MLL) [66]–[68].