Coagulation factors II, VII, IX, X (Factor II (FII, also called Prothrombin), Factor VIIa (FVIIa, activated form of Factor VII), Factor IX (FIX), Factor X (FX))

Coagulation factors II (prothrombin), VII, IX, and X are a group of vitamin K–dependent serine proteases essential for the initiation and propagation of the blood coagulation cascade. Factor II (prothrombin) is the zymogen precursor of thrombin, the central enzyme that converts fibrinogen to fibrin. Factor VII (activated to VIIa), together with tissue factor, initiates the extrinsic pathway, leading to the activation of factors IX and X. Factor IX (activated to IXa) forms a complex with factor VIIIa to efficiently activate factor X in the intrinsic pathway. Factor X (activated to Xa) is the point of convergence for both intrinsic and extrinsic pathways, catalyzing the conversion of prothrombin to thrombin. All four factors share homologous domain organization and require γ-carboxylation (vitamin K–dependent modification) for calcium binding and functional activity. These factors are major therapeutic targets for anticoagulant drugs and are measured clinically to assess bleeding risk or monitor anticoagulant therapy[3][4][5][6][1]. This entry is not a single molecular target but a widely used pharmacological grouping, particularly in the context of anticoagulation and coagulation disorder management. For structured data curation, each factor should be represented individually.

Other names

Vitamin K–dependent coagulation factorsProthrombin complex factorsProcoagulant factors

Inhibition of enzymatic/proteolytic activity (Xa inhibitors, IIa inhibitors). Inhibition of γ-carboxylation (Vitamin K antagonists inhibit post-translational modification necessary for activity). Replacement therapy (supplementation with recombinant or plasma-derived factors).