FCGR2B and Alzheimer disease: Given that FcγRIIb was previously identified as a receptor for Aβ1-42 and a mediator of memory impairment in hAPP-J20 mice expressing only familial mutant APP (Kam et al., 2013), and that tau as well as Aβ is essential for memory impairment in AD mouse (Ramsden et al., 2005), we hypothesized that FcγRIIb is responsible for tau hyperphosphorylation in response to Aβ1-42.