Fc fragment of IgG receptor IIb (FcγRIIB)

CD32B, also known as FcγRIIB, is a low-affinity IgG Fc receptor and a critical regulator of immune cell activation. It is the only inhibitory member among the classical Fcγ receptors and plays an essential role in maintaining immune homeostasis by counterbalancing activating signals from other receptors. It is expressed on B lymphocytes, monocytes, macrophages, basophils, mast cells, granulocytes and platelets. CD32B acts as a negative regulator of cell activation, inhibiting B-cell activation and counterbalancing stimulatory activity from other activating receptors. Deficiency or dysfunction in CD32B leads to heightened antibody responses and increased risk for autoimmune diseases. CD32B has emerged as a promising therapeutic target for B-cell malignancies.

Other names

CD32BFcgR2bIGFRIIBFCGR2B

Monoclonal antibodies targeting CD32B can induce cytotoxicity against malignant B cells through mechanisms requiring intact Fc regions.