Tfh13 cells triggered the production of high-affinity IgE, which led to the induction of anaphylaxis.102 In addition, over the course of Th2-skewed infection (with the helminth Nippostrongylus brasiliensis), the cytokine profile of Tfh cells changes from one dominated by the production of IL-21 to one favoring IL-4-producing Tfh cells. The gene discussed is IGHE; the disease is infection.