Cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) is a common deletion in pediatric and adult B-ALL CNV profiles (1, 57, 64), as well as a major proposition of E2A-PBX1–positive B-ALL, but limited in MLL-rearranged patients (P = 0.005) (65). The gene discussed is CDKN2A; the disease is precursor B-cell acute lymphoblastic leukemia.