Angiopoietin-1 is a 498 amino acid secreted protein that undergoes post-translational glycosylation. It contains 1 fibrinogen C-terminal domain. Angiopoietin-1 is found to bind and activate TIE2 receptors by inducing its tyrosine phosphorylation. It is implicated in endothelial developmental processes later and is distinct from that of VEGF. Angiopoietin-1 appears to play a crucial role in mediating reciprocal interactions between the endothelium and surrounding matrix and mesenchyme. Moreover, it mediates blood vessel maturation/stability. Angiopoietin-1 may also play an important role in early development of the heart. It may have a potential therapeutic utility since it can be used for specifically targeting tumor vasculature or for promoting angiogenic processes in certain organs such as an ischemic heart.