TLR4 and hepatocellular carcinoma: In non-viral HCC, intestinal barrier dysfunction associated with chronic liver diseases due to a high-fat diet, alcohol, or increased levels of secondary bile acids, allows for the entry of intestinal microbiota products into the liver, activating hepatic stellate cells (HSCs) and Toll-like receptor 4 (TLR4), and the concomitant induction of fibrosis and the epithelium-regulated protein growth factor secretion, ultimately promoting the development of liver cancer [119,120].