TLR7 and infection: Forsythiaside A alleviated the symptoms of weight loss and lung tissue damage caused by influenza virus infection in mice by attenuating the mRNA expression of TLR7, MyD88, IRAK4, TRAF6 in TLR7 signaling pathway and NF-κB p65, reducing the gene and protein expression of retinoicacidinduciblegene-1, mitochondrial antiviral signaling protein and NF-κB, and inhibiting the replication of influenza A viruses to control infection (71, 72).