Expansion capacity of Treg cell populations. A, Fold expansion in each Treg cell population was measured after in vitro expansion in the presence of DMSO or TAC (Wilcoxon-matched pair test), comparing day 7 with day 14 cell numbers. B, Ratio of proliferation between each Treg cell population incubated with DMSO or TAC (Mann-Whitney U test). n = 12 donors are shown (*P < 0.05, **P < 0.01, ***P < 0.001). Median with interquartile range is represented.