Sample Types: serum or plasma (citrate, EDTA or heparin). Range: 5 - 80 nmol/L. Sensitivity: 0.2 nmol/l. Time: 4.5 hours ? Endostatin, a 20-kDa C-terminal proteolytic fragment of collagen XVIII, is an endogenous angiogenesis inhibitor localized in the vascular basement membrane in various organs. The biological functions of the endostatin-network involve SPARC, thrombospondin-1, glycosaminoglycans, collagens, and integrins. Endostatin is expressed during the progression of renal fibrosis in tubular cells of injured tissue. In renal micro-vascular disease, observed in late stages of patients with chronic kidney disease, increased endostatin levels are possibly the consequence of enhanced extracellular matrix degradation. Thus endostatin may become an important marker for progressive microvascular renal disease in patients with chronic kidney disease. Endostatin levels in blood are also likely to increase in patients with other microvascular tissue injuries, including atherosclerosis, myocardial- and brain ischemia. In ischemic stroke patients, high endostatin plasma levels predict a worse long-term clinical outcome.