EFS for children with ALL according to NCI risk classification. Probability of EFS for (A) NCI standard-risk patients with (N = 77) and without (N = 1,045) a 9p abnormality; or (B) NCI poor-risk patients with (N = 124) or without (N = 593) a 9p abnormality. Numbers of patients remaining in follow-up are shown in the insets.