http://www.creativebiomart.net/description_382704_12.htm

FcERI, also known as FCER1A, is the alpha subunit of the immunoglobulin epsilon receptor (IgE receptor). IgE receptor is comprised of an alpha subunit(FcERI), a beta subunit, and two gamma subunits. IgE receptor is the initiator of the allergic response. When two or more high-affinity IgE receptors are brought together by allergen-bound IgE molecules, mediators such as histamine that are responsible for allergy symptoms are released. FcERI is glycosylated. It contains 2 Ig-like (immunoglobulin-like) domains.