While these studies exemplified the role of IL-4Rα signaling on specific immune cells (10, 11, 13), it also questioned whether the Th1/Th2 paradigm of resistance/susceptibility to infection was in fact still relevant, considering that in certain disease settings, IL-4/IL-13 signaling essentially instructed a beneficial Th1 response (5, 11). This evidence concerns the gene IL4 and infection.