FCGR2B and infection: All the endodomain-truncated constructs (FcγRIIA-H.∆IC, FcγRIIA-R.∆IC and FcγRIIB.∆IC, corresponding to constructs 2, 6, 11 respectively) were not susceptible to ADE of infection, indicating that binding of anti-Spike IgG-SARS-CoVpp immune complexes was not sufficient to mediate entry and that the signaling-competent endodomain was required.