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. Here, RB1 is linked to acute lymphoblastic leukemia.