Endostatin was originally identified in the culture medium of a murine endothelioma cell line by Michael S. O’Reilly et al., from the laboratory of Dr. Judah Folkman. The same group of investigators has also discovered another angiogenesis inhibitor, angiostatin. The search for angiogenesis inhibitors began with the premise that the primary tumor secretes an inhibitor which suppresses the growth of metastatic cells at secondary sites. Biochemical characterization of endostatin showed a molecular mass of 20 KDa containing 184 amino acid residues. Endostatin selectively inhibits endothelial cells and does not affect the growth of non-endothelial cells, including tumor cells. Recombinant mouse endostatin was initially produced in E. coli...