FCGR2B

Low affinity immunoglobulin gamma Fc region receptor II-b is a is_associated_with::protein that, in humans, is encoded by the FCGR2B is_associated_with::gene. FCGR2B (CD32B) is a "low affinity" receptor for is_associated_with::Immunoglobulin G (IgG). Mutation in the gene in humans leads to a lupus phenotype. The cytoplasmic part of this receptor contains an is_associated_with::immunoreceptor tyrosine-based inhibitory motif, in contrast to the activating is_associated_with::isoform, FCGR2A (CD32A).

Function
The inhibitory CD32B is expressed on is_associated_with::B cells and myeloid is_associated_with::dendritic cells. Ligation of CD32B on B cells downregulates is_associated_with::antibody production and may, in some circumstances, promote is_associated_with::apoptosis. Co-ligation of CD32B on dendritic cells inhibits maturation and blocks cell activation. CD32B may also be a target for is_associated_with::monoclonal antibody therapy for malignancies.