The addition of anti-CD20 monoclonal antibodies such as rituximab or obinutuzumab to chemotherapeutic regimens appears to overcome adverse prognosis associated with monoallelic del(11q) or ATM mutation [26,29], although its impact on CLL with biallelic ATM inactivation remains to be ascertained. This evidence concerns the gene ATM and B-cell chronic lymphocytic leukemia.