Together, our data preclude a role for STAT4 in SLE manifestations in Spt FcγRIIB−/− and Sle1b and TLR7-induced Sle1b models and in promoting AFC, GC, and Tfh responses in autoimmune and foreign Ag–driven responses, including influenza viral infection. Here, FCGR2B is linked to systemic lupus erythematosus.