IL4 and peanut allergic reaction: Recent studies which are consistent with these findings have observed the development of IL-4-producing Tfh cells and investigated how they might be playing a critical role in IgE production in peanut allergy [38,39]; in addition, they also discovered the type 2 subset (Tfh2) within the Tfh which are considered as the major player that secretes IL-4 and promotes isotype switching to IgE after allergen exposure and during intestinal helminth infection [40].