LEF1 and infection: In contrast, infection with the vector encoding Lef1 greatly augmented IFN-γ expression in DKK3-treated FoxO4-cKO cells compared with FoxO4-cKO cells under Th1-polarizing conditions (Figure 6, C and D), indicating that ectopic Lef1 expression in FoxO4-cKO cells could rescue IFN-γ expression after DKK3 treatment.