IgE mediated reactions are actually the best-characterized types of allergy; non-IgE mediated reactions or cell mediated responses include those reactions in which specific cells, different from mastocytes (and basophils), are responsible for the allergic reaction, and they mostly involve the gastrointestinal tract; mixed IgE mediated and cell mediated responses are those reactions in which both IgEs and immune cells are involved [1-4]. The gene discussed is IGHE; the disease is Allergy.