Endostatin is a naturally occurring 20kDa polypeptide derived from the C-terminal portion of type XVIII collagen. It functions as an anti-angiogenic cytokine that is expressed in various organs with the highest levels in liver, lung and kidney. The gene encoding it is localized on human chromosome 21q22.3.
[1][2] Recombinant human Endostatin is a 20.2kDa protein consisting 184 amino acid residues.