On this basis, we subsequently demonstrated the potential clinical utility of the pan-CDK inhibitor roscovitine, which inhibits RNA polymerase II activity and downregulates genes involved in transcription and translation initiation, as well as DNA repair and cellular survival, including antiapoptotic genes such as MCL1, thus targeting the antiapoptotic and other prosurvival properties of p53-defective CLL [57]. This evidence concerns the gene TP53 and B-cell chronic lymphocytic leukemia.