The urokinase-type plasminogen activator system (uPAS) consisting of urokinase plasminogen activator (uPA), an extracellular proteolytic enzyme produced by tumour cells, its receptor uPA-R and their corresponding inhibitors plasminogen activator inhibitors 1 and 2 (PAI-1 and PAI-2) are thought to play a major role in this process. Here, PLAU is linked to neoplasm.