Some of the most adverse prognostic factors in CLL (i.e., age >65 years, Rai stages 2–4, WBC >35 × 109/L, CD38+ cells >30 %, B2M >3 mg/L, LDH >480 IU/L, del 11q and lack of IGVH mutation) were correlated with the decrease of miRNA expression (Tables 6 and 7). This evidence concerns the gene B2M and B-cell chronic lymphocytic leukemia.