Kaplan-Meier estimate of event-free survival of all evaluable patients in trials ALL-BFM 86, 90, and 95. Log-Rank tests: ALL-BFM 86 versus 90, P = .001; ALL-BFM 86 versus 95, P < .001; ALL-BFM 90 versus 95, P = .062. 6y-pEFS indicates probability of event-free survival at 6 years; SE, standard error.