IL4R and helminthiasis: The majority of IL-4Rα−/−IL-5−/− mice contained active adult worm infections and frequency of infection was significantly higher compared with WT or IL-4Rα−/− mice (15/18 mice, versus 5/19 WT and 6/16 IL-4Rα−/− mice, χ2 statistic: 70.61, p < 0.0001; Fig. 4C).