IL-2 affords additional prolongation of the half-life of adoptively transferred Tregs compared with rapa alone. (A) Experimental schema. (B) Longitudinal frequency of CFSE+ Tregs expressed as a percentage of the 1-hour postinfusion measurement. Tregs were defined as CD3+, CD4+, CD2+, and FOXP3+. *P < .05, percentage of CFSE+ Tregs IL-2+rapa vs rapa using repeated-measures analysis of variance (ANOVA). (C) Percentage of all CFSE+ cells that are positive for both CD25 and FOXP3 (left), CD25 only (middle), and negative for CD127 (right). *P < .05, IL-2+rapa vs rapa using repeated-measures ANOVA. NS, not significant.