HNF-4 (Hepatocyte nuclear factor 4), a member of the steroid/thyroid nuclear receptor superfamily, is a transcriptional factor which expresses in the liver, intestine, kidney, and pancreatic cells. It contains several functional domains: a ligand-independent activation domain (AF1), a zinc finger DNA binding domain, and a ligand-dependent activation domain (AF2). HNF-4 binds to a specific DNA element as a homodimer and regulates the expression of many genes, involved in glucose, fatty acid, and cholesterol metabolisms.