IL4 and infection: First, we found that the IL4-Rα−/− mice displayed reduced parasite numbers whereas the cre/LoxP mice showed a minimum infection without signs of reduced immune response capacity; serum IgE, IL-4, and IL-13 production was increased and serum IgG1 production was raised, but IgG2a was reduced in the cre/LoxP mice, altogether indicating that IL-4Rα was functional in other cell types.