IL4R and helminthiasis: Tuft cells constitutively express IL-25 and, after helminth infection, tuft cell-derived IL-25 activates ILC2 to secrete IL-13 that, via IL-4Rα signaling induces tuft cell hyperplasia and increased levels of IL-25 in a feed-forward circuit promoting Th2 responses against helminths26, 27, 28.