PRS by initial RER treatment regimen on CCG-1961. Kaplan-Meier plots of survival for 272 children who relapsed after treatment for NCI high-risk ALL on CCG-1961. The terms “Standard BFM” and “Augmented BFM” refer to the intensity of the initial randomized regimen of PII. The figure shows no significant difference in 3-year PRS as a function of initial treatment intensity.