Plasminogen Activator Inhibitor 1 (PAI-1) is a glycoprotein found in plasma that is implicated in the processes of angiogenesis, hemostasis, tumor metastasis, fibrionlysis, ovulation, embryonic development and inflammation (1). The elevation of PAI-1 has shown to correlate with the prognosis of many cancers including breast cancer (2,3,4). PAI-1 is activated by the glycoprotein vitronectin. Vitronectin binds to PAI-1 and modulates fibrinolysis and cell migration (5). This binding has proven to be an important inhibitor of the activated form of protein C (APC) (6).
