English: Figure 1. Immune pathways triggered by influenza-virus infection. Influenza viruses first infect alveolar or airway epithelial cells. Viral RNA in the cytoplasm is recognized by RIG-I, TLR3, TLR7, and NLR. TLR pathway activates downstream IRF3 and IRF7 to regulate the production of IFNs. Binding viral RNA to the RIG-I receptor can trigger its interaction with MAVS to activate NF-κB. MAVS and NLR activate inflammasomes under the action of viral RNA to release IL-1β and IL-18, thereby forming a cytokine storm.