CDKN2A and acute lymphoblastic leukemia: Amplification of PDGFRA (6/9 ALL-RIG; 11/23 MB-RIG) and loss of CDKN2A/B (4/9 ALL-RIG; 17/23 MB-RIG) represented the most common copy-number alterations (CNAs) in RIGs, with 2/8 ALL-RIG and 8/23 MB-RIG patients exhibiting co-occurrence of both (Fig. 5).