HGF and neoplasm: Tumor cells can actually: (a) produce HGF; (b) secrete PAI-1, which prevents plasminogen activator from cleaving HGF into its component proteins; (c) interfere with blood coagulation in a number of ways, including tissue factor expression and release via microvesicles; production of molecules (like mucin) that control platelet aggregation; and Secretion of cytokines that activate the endothelium.