CD25+ proliferation and suppression are independent functional variables in type 1 diabetes. CD25+ proliferation and suppression are independent functional variables in type 1 diabetes. Control (A) and type 1 diabetes correlation plots (B) between the percentage of PKH-labeled CD4+CD25+ T–cell proliferation and CD4+CD25− target T–cell proliferative suppression. Mean for CD3/CD28 stimulation, 95% CI (dotted lines), linear regression, r2: control CD3/CD28, 0.7345; type 1 diabetes CD3/CD28, 0.027. Correlation statistics by two-tailed Spearman rank correlation test. C: Correlation plots between cytokines in cocultures with type 1 diabetic or control CD4+CD25+ cells and proliferative suppression of CD4+CD25− targets. Correlation statistics by two-tailed Spearman rank correlation test. Ctrl, control subjects; T1D, type 1 diabetes. Angela Hughson et al. Diabetes 2011;60:2125-2133 ©2011 by American Diabetes Association