Summary
In healthy humans, blood vessel-tissue factor is found primarily in the adventitia
and thus physically separated from coagulation factors, which mainly circulate in
an inactive form. Following injury, TF is exposed to blood and initiates the coagulation
cascade. The resulting fibrin formation is an essential part for the initial repair
of vessel damage to minimize blood-loss (reviewed by (1-4). Therefore, TF may be considered
to form a hemostatic sheath around blood vessels essential for hemostasis and appears
to be essential for life inasmuch as no TF deficiency has been reported and TF knockout
mice do not survive beyond the perinatal period.