CpG ODN–induced IFN-γ production is diminished in Tyk2^−/− DCs. Isolated CD11c⁺ DCs from WT, Tyk2^−/−, or Stat4^−/− splenocytes were cultured with CpG ODN for 3 days. The amounts of IFN-γ in the supernatants were measured by ELISA. Data are means (± SD) from 5 independent experiments. ND indicates not detectable. *Significantly different from the mean value of WT DCs, *P < .01.