Mouse Th2 cells, but not naive or Th1 cells, express Amphiregulin (AR), a member of Epidermal Growth Factor (EGF) family. Like other EGF members, AR is expressed as a transmembrane precursor protein and released by proteolytic cleavage [21, 22] . Soluble AR binds to EGF receptors and promotes proliferation and differentiation of epithelial cells, fibroblasts and keratinocytes [23] [24] [25] . AR-deficient mice [26] showed slower kinetics of clearance [27] of the helminth parasite, Trichuris muris, that is cleared most effectively by Th2-biased responses. AR production is also induced in human mast cells by IgE cross-linking [28, 29] , in human eosinophils by IL-5 [30] , and in human basophils by IL-3 [31] . Thus AR is induced by activation of at least four cell types contributing to Type 2 inflammation, suggesting a role for AR during an allergic immune response. In addition, production of AR by immune cells is potentially important for tissue remodeling and repair [21, 26] during and after damaging immune responses.