A, Highest category of somatic mutation per participant identified by tumor whole-exome sequencing (WES). Data for the subsets of children with central nervous system (CNS) tumors (n = 40) and non-CNS tumors (n = 81) are shown in addition to the entire patient cohort with tumor samples available (n = 121). I indicates category I mutation; II, category II mutation; III, category III mutation; IV, category IV or no mutation. B, Genes targeted by recurrent somatic mutations in patients for whom tumor WES was performed.