These allergen-specific IgE-bearing cells are now sensitized against the allergen and may trigger an allergic reaction upon the next contact with the allergen if at least 2 IgE antibodies on mast cells are bound to the allergen at the same time, a phenomenon called “bridging”, that leads to an allergen-specific mast cell degranulation and histamine release. The gene discussed is IGHE; the disease is allergic disease.