Stat4 is required for optimal IL-17 but not IL-4 or IL-10 expression. A, Eight weeks after cell transfer, T cells were isolated from MLN and restimulated with PMA and ionomycin in the presence of monesin for 4 h, and IL-17 and IL-10 expression on gated CD4 cells was measured by intracellular staining. B, Real-time RT-PCR for IL-17, IL-4, IL-10, and c-Maf expression in MLN CD4 T cells. *p < 0.05. C, Real-time RT-PCR for IL-17 and IL-10 expression in wild-type, DKO, and TKO CD4+CD25− T cells after 2 d of culture with anti-CD3 and anti-CD28, combined with IL-6, IL-27, or IL-6 plus IL-27.