During time course infection experiments, although infection is beginning to be cleared in WT animals at 5 wk postinfection (mean 2% parasite recovery and sterilizing immunity evident in ∼50% of animals) (18), 9/10 IL-4Rα−/− mice contained adult B. malayi, and levels of motile parasites were not significantly different to numbers of surviving larvae at 2 wk postinfection (Fig. 1A). The gene discussed is IL4R; the disease is infection.