Factor XI (凝血因子 XI)

Factor XI is an important protein in the blood coagulation cascade, and is part of the intrinsic coagulation pathway. As a zymogen, Factor XI circulates in an inactive form in the blood. When blood vessels are damaged, Factor XI is activated to Factor XIa, which then activates Factor IX, leading to the activation of Factor X. This cascade ultimately generates thrombin, promoting blood clotting, sealing the blood vessel damage, and stopping bleeding.
Factor XI is crucial for maintaining normal hemostatic function, but abnormal activity can lead to bleeding or thrombosis. Factor XI deficiency (Hemophilia C) is a genetic disorder that predisposes individuals to spontaneous or trauma-induced bleeding. On the other hand, excessive Factor XI activity is associated with thrombosis and may increase the risk of deep vein thrombosis, pulmonary embolism, and stroke^[1].