FCGR2B and infection: Flow cytometry data revealed that Raji cells express relatively high levels of FcγRIIB, that THP-1 cells express high levels of FcγRIA and FcγRIIA, and that K562 cells express high levels of FcγRIIA, suggesting that high levels of FcγRIIB but not FcγRIIA are required for ADE of infection [25].