Elevated IFN-γ and IL-17 production in IL-2–KO CD4⁺ T cells. Lymph node cells from 3- to 4-week-old mice were stimulated with or without 50 ng/mL PMA and 500 ng/mL ionomycin for 5 hours, and cytokine production in CD4⁺ T cells was evaluated by intracellular cytokine staining. The percentage of cytokine-producing CD4⁺ T cells was measured by flow cytometry. (A) FACS profiles are representative data from one experiment. (B) Bar graphs represent mean plus or minus SD of 5 mice from independent experiments. *P < .001; ***P < .05.