FCGR2B and rheumatoid arthritis: Some studies found no differences between RA patients and healthy controls (60, 64–66), whereas others reported that monocytes, mo-DCs, monocyte-derived macrophages, and synovial macrophages of RA patients displayed elevated levels of activating receptors FcγRIIa and FcγRIII, while expression of inhibitory receptor FcγRIIb was similar to healthy controls (9, 10, 29, 57, 67, 68) (Figure 2A).