Influence on relapse of MRD_pre-HCT and MRD_post-HCT. HRs for relapse from a Cox regression model (A) considering only pre-HCT MRD or considering only post-HCT MRD treated as time-dependent covariate (B) with both variables MRD_pre-HCT as a fixed covariate and MRD_post-HCT as a time-dependent covariate. Cumulative hazard of relapse from children with ALL who were MRD positive before HCT low (C), high (D), and very high (E). The MRD values after transplant are MRD negative (neg; solid red line), MRD low positive (dashed light green line), MRD high positive (solid blue line), and MRD very high positive (dashed purple line); the values were treated as time-dependent covariates. The vertical line represents an HR of 1 for reference.