Low-dose IL-2 improves in vitro CD4Treg-suppressive activity. Suppressive activity of patient CD4Tregs was tested against HD CD4Tcons in vitro. Patient CD4Tregs were assessed at baseline (W0) and at week 6 (W6). In addition, the ability of HD CD4Tregs to suppress the proliferation of patient CD4Tcons was assessed at both time points. Box plots depict the 75th percentile, median, and 25th percentile values; whiskers represent maximum and minimum values, except for outliers. The box for HD is shaded in gray. P values comparing HD CD4Tregs to patient CD4Tregs are shown at week 0 and week 6. Patient CD4Treg suppression of patient CD4Tcons between baseline and week 6 and suppression of patient CD4Tcons by HD CD4Tregs at baseline and week 6 were also compared; 2-sided Wilcoxon signed-rank test. Number of patients evaluated at each time point is indicated at the bottom of the image. For the HD control column, N represents the number of assays using cells from the same HD.