Table 2  Properties of FcγR.
Receptor  Affinity  IgG specificity  Cell distribution
FcγRI  High  IgG1, IgG3, IgG4  Induced by interferon‐γ on monocytes, neutrophils, macrophages, dendritic cell subpopulations; mast cells
FcγRIIa  Low  IgG1, IgG3, but IgG2 binding limited to the FcγRIIa‐H131 form, ~70% people)  All leukocytes and platelets except T and B lymphocytes
FcγRIIc a  Low  IgG1, IgG3, IgG4  NK cells
FcγRIIIa  Low  IgG1, IgG3.  NK cells, macrophages, subpopulation of circulating monocytes, myeloid dendritic cells, neutrophils at very low levels
Binding avidity reduced by Phe at position 158
FcγRIIIb  Low  IgG1, IgG3  Neutrophils
FcγRIIb  Low  IgG1, IgG3, IgG4  B lymphocytes, some monocytes (can be upregulated); basophils; eosinophils? Plasmacytoid and myeloid dendritic cells; NK cells only of individuals with FcγRIIIb gene copy number variation
Airway smooth muscle, LSEC, placenta, follicular dendritic cell
Ig, immunoglobulin; NK cell, natural killer cell.
a  Expressed in 20% of people.
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