TLR4 and metabolic dysfunction-associated steatohepatitis: Singh et al. (2011) revealed that the expression of TLR4 mRNA and its protein in normal liver tissues was lower than that in NASH patients. This suggested the importance of immunological inhibition and immune tolerance in the normal liver. Sharifnia et al. (2015) found that the expression of TLR4 mRNA and interferon regulatory factor-3 (IRF-3) mRNA in the liver of NASH patients were significantly increased compared with NAFLD patients.