TLR4 and infection: After infection with F. necrophorum, the protein expression of TLR2 (Figure 9B), TLR4 (Figure 9C), TRAF2 (Figure 9D), MyD88 (Figure 9E), the protein expression ratio of the pp65/p65 (Figure 9F), and the protein expression ratio of the p-JNK/JNK (Figure 9G) significantly upregulated (P < 0.05), the protein expression ratio of the IκB-α (Figure 9H) significantly downregulated (P < 0.05).