Encoded by human PLG Gene (Plasminogen Family) and expressed in the kidney, angiostatin is an angiogenesis inhibitor present in plasma and other extracellular fluids that blocks neovascularization and mediates suppression of metastases. Containing at least three kringles, angiostatin is a 38-kD internal (serine protease) proteolytic fragment of plasminogen. OR A procedure to enlarge the opening in a blood vessel that has become narrowed or blocked by plaque (a buildup of fat and cholesterol on the inner wall of the blood vessel). Examples of angioplasty are balloon angioplasty and laser angioplasty.