ATM and B-cell chronic lymphocytic leukemia: 16 reported the involvement of ATM and BIRC3 in 11q deletion. As the del(11q) was present in more than a half of our cohort of 2p+ CLL cases, we investigated the two genes. We found that del(11q) involves both genes in the majority of cases, and that BIRC3 is never deleted alone (as also shown by another group21).