TLR9 and influenza: We asked whether endosomal viral‐sensing TLR signals in the B cells or in other innate cells, known to be strongly induced by influenza RNA, are required for iABC generation We found that iABC did not develop in response to influenza infection, in either aged TLR7−/− or TLR9−/− mice, indicating that both TLR are required for iABC generation (Figure 5).