CD32 is a surface receptor protein and part of a large population of B cell co-receptors. It has a low-affinity for IgG antibodies and down-regulates antibody production in the presence of IgG. This feedback loops essentially lowers the production of IgG produced by B cells when there is a surplus in the body.Monoclonal antibodies can distinguish between type A and type B.Receptors for the Fc portion of IgG such as FCGR2A play an essential role in the protection of the organism against foreign antigens by removing antigen-antibody complexes from the circulation. Receptors are present on monocytes, macrophages, neutrophils, natural killer (NK) cells, and T and B lymphocytes, and they participate in diverse functions such as phagocytosis of immune complexes and modulation of antibody production by B cells.