Somatic chromosomal aberrations, such as hyperdiploidy (n, 10), translocation with the fusion transcript ETV6-RUNX1 (n, 7) TCF3-PBX1 (n, 4), t(2;14)(p10;q23) and t(5;15)(q12;q13) and complex karyotype (n, 3) were found in ALL cases older than 12 months of age at the diagnosis. The gene discussed is PBX1; the disease is acute lymphoblastic leukemia.