VTN and neoplasm: One such effector mechanism subverted by the neoplastic process is the urokinase plasminogen activator system, which directly and indirectly promotes tumour cell invasion and metastasis through multiple mechanisms including plasmin-mediated pericellular proteolysis, enhanced vitronectin adhesion and activation of pro-metastatic intracellular pathways such as src and ERF 1 and 2 (Ahmed et al, 2003; Sidenius and Blasi, 2003).