Box-plots show the kinetics of CD127-Foxp3⁺ cells. Proportions and absolute numbers of peripheral blood Treg were determined before and after the infusion of fresh culture-expanded UCB Tregs that were administered 1 day after UCB transplantation (all patients) and again, before and after the infusion of thawed UCB Treg (same donor) 15 days after UCB transplantation (11/17 recipients of CsA/MMF and 6/6 recipients of sirolimus/MMF). In the plot, the cross represents the median value, the box represents the interquartile range, and the vertical line represents the range of the results. Panels A and B show the proportion and absolute number per microliter of peripheral blood CD127-Foxp3⁺ cells within the CD4⁺ subset, specifically in recipients of CsA/MMF. Panels C and D show the proportion and absolute number per microliter of peripheral blood CD127-Foxp3⁺ cells within the CD4⁺ subset, specifically in recipients of sirolimus/MMF. In a subgroup of 7 patients who had informative HLA discrepancies and received infusions on day +1 and +15 that could be studied by flow cytometry depicting the proportion (E) and absolute numbers per microliter (F) of peripheral blood CD4⁺CD127−Foxp3⁺ cells derived from the regulatory T-cell donor unit. (*) In panel B, at the pretransplantation time point the figure excludes one outlier with an absolute Treg count of 152/μL.