An endostatin is a naturally-occurring fragment of one of the collagen proteins, found in the human body, that is reported to serve as an anti-angiogenesis agent. Similar to angiostatins, endostatins may interfere with the binding of growth factors (such as vascular endothelial growth factor, or VEGF) by inhibiting them. In other words, endostatins are reported to block the attachment of growth factors to angiogenesis factors.

Endostatins are currently being studied as part of cancer research; they hold great potential, along with angiostatins, in stopping the spread of cancerous tumors.

Endostatin