F3

F3 is a transmembrane glycoprotein comprising 263 amino acids, initiates blood coagulation by binding to factor VII/VIIa. Acting as an "anchor" to the cell membrane, F3 localizes the coagulation process to the site of injury and activates factors IX and X, triggering the amplification loops of both the intrinsic and extrinsic pathways of thrombosis. Despite this, F3 and FⅦ lack procoagulant activity when present alone at physiological concentrations. Often associated with enhanced blood coagulation in cancer patients, F3's overexpression on tumor endothelial and cancer cells may contribute to thrombosis within tumor tissues. The elevated expression of F3 influences cellular behaviors such as proliferation, invasion, and metastasis, positioning it as a promising therapeutic target in oncology.