FCGR2B and systemic lupus erythematosus: Indeed, the inhibition of Syk activity is known to harness multiple downstream signaling pathways, which supported possible effectiveness of Syk inh against lupus, as indicated by i) the reduced Syk activation in several organs and lupus activity attenuation in FcγRIIb−/− mice with fostamatinib (R788), and ii) a decrease in ETs and pro-inflammatory responses in FcγRIIb−/− macrophages and neutrophils.