TLR4 and hepatitis C virus infection: Elevated serum levels of Toll-like receptor 4 (TLR4) have been shown to play a significant role in the progression of liver fibrosis, particularly in nonalcoholic steatohepatitis (NASH) and other chronic liver diseases, such as viral hepatitis C. Studies indicate that serum TLR4 levels are directly correlated with the degree of liver fibrosis in patients with NASH, with a progressive increase in these levels observed as fibrosis advances from the F0 to F4 stage [15].