Recurrent cytogenetic aberrations include: deletion at 13q14.3 (55% of cases) is associated with an indolent form and loss of miR-15a and miR-16-1 genes;5 deletions at 17p13 (7%) or 11q22-23 (18%) with consequent loss of TP53 at 17p, ATM and miR-34b/miR-34c at 11q are associated with a more aggressive form;6, 7 trisomy 12 (16%) is associated with an intermediate form of CLL. This evidence concerns the gene ATM and B-cell chronic lymphocytic leukemia.