Angiopoietin-related protein 4 (ANGPTL4) is also known as Hepatic fibrinogen / angiopoietin - related protein (HFARP), ARP4, PGAR. ANGPTL4 contains one fibrinogen C-terminal domain. ANGPTL4 is a homooligomer , and the homooligomer undergoes proteolytic processing to release its carboxyl fibrinogen-like domain, which circulates as a monomer. The homooligomer unprocessed form is able to interact with the extracellular matrix. ANGPTL4 may act as a regulator of angiogenesis and modulate tumorigenesis. ANGPTL4 inhibits proliferation, migration, and tubule formation of endothelial cells and reduces vascular leakage. ANGPTL4 may exert a protective function on endothelial cells through an endocrine action.