Endostatin has been identified as a C-terminal fragment of Collagen type 18, a recently identified member of a family of collagen-like proteins referred to as multiplexin family Endostatin specifically inhibits proliferation of endothelial cells althoμgh it does not affect the proliferation of EOMA cells. Endostatin also potently inhibits angiogenesis and tumor growth. Endostatin has an important role in endothelial cell adhesion and cytoskeletal organization. Endostatin can be found in vessel walls (elastic fibers) and basement membranes. Recombinant Endosatin expressed in yeast causes G1 arrest of endothelial cells, and endostatin treatment results in apoptosis of HUVE and HMVE cells.