To this aim, we selected 3 subpopulations of B-ALL samples classified according to their primary genetic alterations as: proB-ALL with MLL rearrangement t(11q23) (n = 55); preB-ALL without t(9;22) (n = 232); preB-ALL with t(9;22) (n = 111). This evidence concerns the gene KMT2A and acute lymphoblastic leukemia.