Table 1.

The roles of STAT family in hepatic fibrosis.

STAT Proteins	Major Triggers or Cytokines	Possible Roles in Fibrotic Liver
STAT1	IFN-α, IFN-β, IFN-γ	Hepatic Stellate Cells→Loss→Inhibited proliferation, increased apoptosis and blocked cell cycle Hepatocytes→Inhibition of liver regeneration, and pro-apoptosis
STAT2	IFN-α, IFN-β, IFN-λ	Promote antiviral responses Protect against hepatic fibrosis
STAT3	IL-6, IL-22	Hepatocytes→Loss→Increased inflammation in the CCl4-induced chronic model Hepatocytes→Loss→Reduced inflammation in the CCl4-induced acute model
STAT4	IL-12, IFN-γ	Impaired STAT4 phosphorylation→liver inflammation and fibrosis Promotes liver inflammation
STAT5	GH, IL-2, IL-3, IL-5	Hepatocytes→Loss→Increased TGF-β levels, increased the sensitivity of Kupffer or hepatic stellate cells to TGF-β Hepatocytes→Loss→Reduces proliferation Antifibrotic effects in the mouse model of cholestasis
STAT6	IL-4, IL-13	Hepatocytes→Loss→Reduced collagen deposition Hepatic Stellate Cells→Promotes liver fibrogenesis Promotes inflammation in hepatitis Protects against ischemia/reperfusion and inflammation of drug-induced liver injuries

References are cited in the text.