TLR9 and metabolic dysfunction-associated steatohepatitis: Additionally, translocated bacterial DNA binds to TLR9 on Kupffer cells in choline-deficient amino acid-defined (CDAA) diet-induced NASH mice, leading to the synthesis of IL-1β, which prompts lipid accumulation and cell death in hepatocytes while triggering the activation of hepatic stellate cells (HSCs) to cause liver fibrosis [133].