Acting as a pan-CDK-inhibitor (targeting CDK1, 2, 4, 6, 7 and 9) [26], its first results in phase I studies in chronic lymphocytic leukemia (CLL) seemed encouraging, as most of the patients had a reduction in tumour mass; some even had complete responses [27]. This evidence concerns the gene CDK1 and B-cell chronic lymphocytic leukemia.