Upon repeated exposure to the allergen, cross-linking of these FcεRIs receptors with allergen-specific IgE leads to degranulation of mast cells and basophils involved in Th2 response and a type I hypersensitivity reaction, culminating in clinical phase of the manifestation of food allergy (5, 6, 15, 17, 36, 52, 68, 69). The gene discussed is IGHE; the disease is food allergy.