TLR9 and fatty liver disease: Mechanistically, GCA activates macrophages via TLR9(Toll Like Receptor 9)‐NF‐κB(nuclear factor kappa‐B) signaling, and activated macrophages promote hepatocyte lipid accumulation and apoptosis via secretion of IL‐6, Tumor Necrosis Factor α (TNFα) and Interleukin‐1β(IL‐1β), thereby leading to hepatic steatosis and inflammation.