During human helminth infection (which causes IgE and IgG4 elevation), Tregs that produce IL-10 and inhibit effector T cells can be found in the peripheral blood and may play a role in limiting inflammation (90), while in murine models of helminth infection, Tregs expand, produce IL-10, and can limit the Th1 more than the Th2 response (91). This evidence concerns the gene IGHE and helminthiasis.