High levels of candidate marker expression help to identify the blast population at diagnosis and early treatment time points. Comparison of the marker expression in leukemic cell populations (ALL) and the residual nonmalignant CD19+ population (in-sample control, CTR). Shown are the MFI measured for indicated markers in newly diagnosed leukemia samples (n = 86) (A) and MRD samples at day 15 (n = 45) of the treatment (B). Represented are data from 3 independent patient cohorts; for simultaneous representation, the median value for each cohort was adjusted. Values for a population size <100 events at diagnosis or <30 events in MRD samples were excluded. Each point represents a single measurement, and gray bars represent the median value for the group. The asterisk indicates a statistically significant difference in marker expression between paired measurements by Wilcoxon matched pairs test. No difference was detected between ALL and control samples for CD31 and CD305.