Comparison of the MRD levels in ALL patients. Comparison of the MRD levels in ALL patients measured by Ig/TCR vs BCR-ABL1 transcript quantification (A) as well as vs BCR-ABL1 genomic breakpoint quantification in all samples (B) and separately in selected time points during frontline treatment (C). Samples from patients with major-BCR-ABL1 fusion variant are shown as triangles and minor-BCR-ABL1 as circles. Samples from patients with concordant MRD course are in red, and samples from patients with discordant MRD are in blue. The light gray diagonal shape represents the area of concordance ±1 log. D, day; W, week (from the start of treatment).