Higher expression in cultured CLL lymphocytes was observed for genes encoding anti-apoptotic proteins: BCL2, BCL2A1, SURVIVIN, XIAP, and regulators of the cell cycle, differentiation and transcription: CDK4, E2F3, CDK9, CDK5R1, MAPK3, MAPK7, and CDKN1C (Table 3). Here, CDK9 is linked to B-cell chronic lymphocytic leukemia.