TLR4 and Cognitive impairment: Promoting M2 polarization and the occurrence of liver fibrosis[139].Acting as a potential receptor to bind to tissue-resident macrophages and recruiting inflammatory monocytes during infection, then inducing an anti-inflammatory phenotype in macrophages[140].Alleviating dysbiosis of the gut microbiota and treating cognitive impairment induced by a high-fat diet[141].Inducing antitumor immune response[142–143].Inhibiting TLR4-mediated inflammatory signaling pathway through regulating the C-Raf protooncogene, serine/threonine kinase (cRAF) phosphorylation pathway[144].