Highly pathogenic avian influenza virus (HPAIV) H5N1 infection can upregulate chTLR3 and IFN-β expression in the lungs and brain of infected chickens [37], while chTLR3 in the lungs, gut, and bursa is rapidly upregulated by low pathogenic avian influenza virus (LPAIV) H7N1 at the early stages of infection [45]. This evidence concerns the gene IFNB1 and infection.