Kaplan-Meier estimates of RFS based on the gene expression classifier for RFS and end-induction (day 29) MRD. (A) Day 29 flow cytometric measures of MRD separated patients into 2 groups with significantly different RFS. (B-C) After dividing patients by their end-induction flow MRD status, an independent effect of the gene expression classifier for RFS is observed among both the flow MRD-negative (< 0.01% blasts; B) and flow MRD-positive (> 0.01% blasts; C) patients. (D-E) Combining the risk scores determined from the gene expression classifier and flow MRD yields 4 distinct outcome groups; the 2 discordant groups show no significant difference in RFS (P = .572) and are therefore collapsed into an intermediate-risk group for RFS prediction (E). (E) The hazard ratios (HR) and corresponding P values are based on the Cox regression (medium-risk vs low-risk, HR = 3.73, P = .001; high-risk vs medium-risk, HR = 2.27, P = .002). The P value reported in the lower left corner corresponds to the test for differences among all groups.