Therefore, as they are closely involved in the modulation of IgE-mediated anaphylactic degranulation, CD300 molecules, not only CD300a, but also CD300c and CD300f, and their ligands, should be considered as novel therapeutic targets for anti-allergic therapy, providing a valuable tool for the treatment of allergy and mast cell-associated disorders. The gene discussed is IGHE; the disease is allergic disease.