The plasminogen activating system has been well-appreciated for its roles in fibrinolysis and metastatic cancer for over 30 years. These observations lead to the clinical development of the key plasminogen activators, namely urokinase (u-PA), and tissue-type plasminogen activator (t-PA) as thrombolytic agents, initially for myocardial infarction in the mid-1980's, and a decade later for use in ...