FCGR2B and Alzheimer disease: Recently, we showed that Fc gamma receptor IIb (FcγRIIb) is also expressed in neurons and directly interacts with Aβ1-42 to mediate Aβ neurotoxicity, synaptic dysfunction, and memory impairment in AD pathogenesis (Nimmerjahn and Ravetch, 2008; Kam et al., 2013).