There was no significant difference between adult and non-HD pediatric ALL in terms of deletions of 3p14.2 (FHIT), 9p21.3 (CDKN2A/B), 9p13.2 (PAX5), 13q14.2 (RB1), and 17q11.2 (NF1), and adult ALL showed more frequent deletion of 17p (TP53) and duplication of 17q than non-HD pediatric ALL (11% vs. 2%, and 9% vs. 1%, respectively). This evidence concerns the gene PAX5 and acute lymphoblastic leukemia.