Transgenic expression of Cyclon fails to restore defective T-reg development in IL-2R–deficient mice. (A) T-regs in spleens from IL-2Rα⁺, Cyclon Tg IL-2Rα⁺, IL-2Rα⁻, and Cyclon TgIL-2Rα⁻ mice. (B) Lack of T-regs in Cyclon-Tg γc⁻ mice. Splenocytes from 8-week-old mice were stained with mAbs to FITC-conjugated anti-CD4 Ab and PE-conjugated anti-Foxp3 Ab. Percentages of T-regs in CD4⁺ T cells are shown in red.