Nonredundant role for WASp in IL-4 but not IFNγ production. WT and WAS^−/− Th1- and Th2-primed OTII TCR Tg⁺ CD4 T cells were restimulated with plate-bound anti-TCRβ (left panels) or pOVA/APC (WT T-depleted splenocytes; right panels) for 24 hours, and the supernatants collected for cytokine detection by ELISA. Results represent 1 of at least 4 comparable experiments. *P ≤ .01 for differences between WT and WAS^−/− T-cell cytokine production, Student t test. Error bars indicate mean and SEM.