PRT-treated platelet transfusion may induce early T_reg-cell activity but no indicators of T-cell anergy. Splenocytes from mice described in Figure 3 were evaluated for markers of regulatory T cells and T-cell anergy. Representative gating selected for CD3⁺ CD4⁺ T cells that were positive for CTLA-4⁺ or TGF-β⁺ (A), regulatory FoxP3⁺ (B), regulatory FoxP3⁺/CD25⁺ (C), a subset of regulatory FoxP3⁺ CD25⁺ cells that were CTLA-4^Hi or TGF-β^Hi (D), and anergic CD3⁺ CD4⁺ T cells by CD44⁺/FoxP3⁻ folate receptor 4 (FR4)^Hi/CD73^Hi events (E). Frequencies (middle) and total numbers (right) are plotted. Notation indicates significance between groups. Data from 2 independent experiments (n = 5 per group) are shown, and bars indicate mean and standard deviation. *P < .05, **P < .01, ***P < .001, ****P < .0001.