TSLP and infection: In response to infection with GI helminths, tuft cells release IL-25 that activates ILC2 to release IL-4, which may feed back on to the epithelium to evoke goblet cell hyperplasia and act as a catalyst for Th2 cell polarization [21] (the transporting epithelial cells may also be a source of IL-25 and other alarmins including IL-33 and thymic stromal lymphopoietin (TSLP)) [22].