Tissue Factor (TF) is a single-pass type I membrane glycoprotein member of the tissue factor family. TF expression is highly dependent upon cell type. This factor enables cells to initiate the blood coagulation cascades, and it functions as the high-affinity receptor for the coagulation factor VII. TF initiates blood coagulation by forming a complex with circulating factor VII or VIIa. The complex activates factors IX or X by specific limited protolysis. TF plays a role in normal hemostasis by initiating the cell-surface assembly and propagation of the coagulation protease cascade.