Evolutionary trajectories of NT5C2 mutations after first relapse. (A) The Sankey diagram illustrates the fate of 46 NT5C2 mutations from 34 first relapses in follow-up samples taken at the time of nonresponse to treatment or second relapse of the patients. All 46 mutations were tracked sensitively by p.R39Q, p.R238W, p.R367Q, p.K404N, or p.P414S ASQ-PCR. (B) Quantitative levels of NT5C2 mutations (red dots) at first relapse and at the end of relapse induction treatment in 16 patients with clonal and in 14 patients with subclonal mutations only. All NT5C2 mutations were tracked sensitively by p.R39Q, p.R238W, p.R238L, p.R367Q, p.K404N, or p.P414S ASQ-PCR. Minimal residual disease levels (blue dots) were assessed by immunoglobulin/ T-cell receptor (Ig/TCR) gene rearrangement quantification and are given as a measure of the overall leukemic burden in the patients at the end of induction treatment. Pt. ID, patient identifier.