Microdeletion studies by Paulsen et al. [28] using genome wide array analysis showed involvement of 7p12.2 (IKZF1), 9p21.3 (CDKN2A), 9p13.2 (PAX5), 12p13.2 (ETV6), 13q14 (RB1), 19p13.3 (TCF3) in association with hyperdiploid ALL. This evidence concerns the gene CDKN2A and acute lymphoblastic leukemia.