To determine the PRRs and cytokine levels following the infection of the H5N6 viruses at the early stage, we further measured the expression of the TLR3, TLR7, RIG-I mRNA, and a set of representative cytokines in the brains and lungs of mice at 3 and 5 DPI using qRT-PCR (Figure 6A–D). The gene discussed is TLR3; the disease is infection.