Factor VIIa and tissue factor--from cell biology to animal models.

Binding of factor VIIa (FVIIa) to tissue factor (TF) and the subsequent initiation of the clotting cascade is essential for hemostasis. However, the aberrant expression of FVIIa-TF contributes to thrombosis. Despite the tremendous progress made in the past 25years in understanding the molecular mechanisms involved in the interaction between FVIIa and TF, there is less known about the cell biology of these proteins. Availability of hemophilic mice (by specific knock-out of FVIII or FIX genes) and novel TF transgenic mice has allowed us in recent years to investigate the importance of TF-FVIIa-induced coagulation from wound healing to sepsis. This supplement explores new aspects of TF-FVIIa biology, with a particular focus on structural biology, cell biology and animal models.