Angpt1 gene encodes a secreted glycoprotein called Angiopoietin 1 that activates the receptor by inducing its tyrosine phosphorylation. It appears to play a crucial role in mediating reciprocal interactions between the endothelium and surrounding matrix and mesenchyme. It may also mediate blood vessel maturation/stability, and may be involved in early development of the heart. Angiopoietin 1 is a member of angiopoietin proteins family that plays important roles in vascular development and regulation of angiogenesis. All angiopoietins bind with similar affinity to an endothelial cell-specific tyrosine-protein kinase receptor.