Factor VII is one of the proteins that causes blood to clot in the coagulation cascade. It is an enzyme of the serine protease class. A recombinant form of human factor VIIa has U.S. Food and Drug Administration approval for uncontrolled bleeding in hemophilia patients. It is sometimes used unlicensed in severe uncontrollable bleeding, although there have been safety concerns.
The main role of factor VII (FVII) is to initiate the process of coagulation in conjunction with tissue factor (TF/factor III). Tissue factor is found on the outside of blood vessels – normally not exposed to the bloodstream. Upon vessel injury, tissue factor is exposed to the blood and circulating factor VII. The gene for factor VII is located on chromosome 13 (13q34).