Plasminogen activator inhibitor 1 (PAI-1) or serine protease inhibitor E1 (SERPINE1) gene is mapped to human chromosome 7q22.1. PAI-1 is produced in hepatocytes, endothelial cells, smooth muscle cells, megakaryocytes, and adipocytes.
Plasminogen Activator Inhibitor 1 (PAI-1) protein belongs to the Serpin superfamily of serine protease inhibitors. It is the principal inhibitor of tissue plasminogen activator (tPA) and urokinase (uPA), the activators of plasminogen and therefore inhibits the fibrinolysis process. PAI is involved in extracellular matrix remodeling and has been implicated in processes like angiogenesis, chemotaxis, ovulation, and embryogenesis. PAI-1 is present in increased levels in various disease states such as a number of cancer forms, obesity and the metabolic syndrome.