In this study, we investigated the relationship between T reg and Th2 cells during an infection with the intestinal helminth H. polygyrus and after HDM-induced airway allergy and observed that type-2 immunity involved the expansion of a functional population of ex-Foxp3 Th2 cells with varying degrees of dependency on IL-4Rα expression on T reg cells. The gene discussed is IL4R; the disease is infection.