Fcg RII, also known as CD32, is a group of three closely related proteins (Fcg RIIA, Fcg RIIB, Fcg RIIC) that share greater than 94% aa identity in their extracellular domains. They function as transmembrane receptors for the Fc portion of IgG molecules. These proteins are expressed by various hematopoietic cells including monocytes, macrophages, neutrophils, NK cells, T cells, and B cells. The Fcg RII proteins are involved in phagocytosis of immune complexes and modulation of antibody production by B cells.