In the setting of Gram-negative bacterial infection, the TLR-4-mediated LPS-TLR4-NF-κB signaling pathway plays an important role in inducing the release of inflammatory mediators such as TNF-α and IL-6 [42] to involve in the anti-infection and inflammatory reactions by the innate immunocytes (e.g., mononuclear macrophages). This evidence concerns the gene TLR4 and infection.