The cross-linking of FcεRI receptor-bound allergen-specific IgE on effector cells (mast cells and basophils) by allergen encounter is the signal for cell degranulation and release of mediators (e.g., histamine, chemotactic factors, leukotrienes, neurokinins, complement anaphylatoxins and others) causing severe allergic reactions, which manifest by anaphylactic shock and even death [8,9]. The gene discussed is IGHE; the disease is allergic disease.