Initiates blood coagulation by forming a complex with circulating factor VII or VIIa. The [TF:VIIa] complex activates factors IX or X by specific limited proteolysis. TF plays a role in normal hemostasis by initiating the cell-surface assembly and propagation of the coagulation protease cascade. Interacts with HSPE; the interaction, inhibited by heparin, promotes the generation of activated factor X and activates coagulation in the presence of activated factor VII. Additional isoforms may exist. Lung, placenta and pancreas. TF expression is highly dependent upon cell type. TF can also be induced by the inflammatory mediators interleukin 1 and TNF-alpha, as well as by endotoxin, to appear on monocytes and vascular endothelial cells as a component of cellular immune response. Belongs to the tissue factor family. Tissue factor entry