TLR4 and Hepatic fibrosis: The TLR family are transmembrane proteins on intrahepatic cells that activate the innate immune system by recognizing microbiota and metabolites from the intestine, of which, TLR2, TLR4, TLR5, TLR7, and TLR9 can be involved in liver fibrosis, with TLR4 currently being the most studied (Seki et al., 2007; Seki and Schnabl, 2012; Chen et al., 2019a; Lee and Suk, 2020).