Survival probability based on the level of MRD stratified by leukemia type and treatment era. Probability of survival during the observation period in patients with ALL (A) or AML (B) after HCT in the earlier era (red) or the recent cohorts (blue). The confidence bands represent 95% CI limits. Both ALL and AML patients treated in the recent era fared significantly better than those in the early era (P = .005 and P = .007, respectively). The impact of MRD level on survival was significant for ALL (P = .002) but not for AML (P = .18).