Angiopoietin 4 is a glycosylated protein with a fibrinogen C terminal domain. It is induced under hypoxic conditions in endothelial cells and is the target of peroxisome proliferation activators.

Angiopoietin 4 is a serum hormone directly involved in regulating glucose homeostasis, lipid metabolism, and insulin sensitivity and also acts as an apoptosis survival factor for vascular endothelial cells. It may play a role in several cancers and it also has been shown to prevent the metastatic process by inhibiting vascular activity as well as tumor cell motility and invasiveness. Decreased expression of this protein has been associated with type 2 diabetes. Alternatively spliced transcript variants encoding different isoforms have been described