Thrombin generation and fibrin network in hemophilia. (A) TF-induced (1 pM) thrombin generation in PRP from F8^−/−Pros1^+/+ and F8^−/−Pros1^−/− mice depicting TFPI-dependent PS activity. (B) APC-dependent PS activity in PRP and PFP from F8^−/−Pros1^+/+ and F8^−/−Pros1^−/− mice. (C) Representative scanning electron microscopy images from F8^+/+Pros1^+/+, F8^−/−Pros1^+/+, and F8^−/−Pros1^−/− fibrin structure and from F9^+/+Pros1^+/+, F9^−/−Pros1^+/+, and F9^−/−Pros1^−/− fibrin structure (Scale bars: 1 μm). (D-G) Thrombin generation triggered by low TF concentration (1 pM) in PFP (D-E) and PRP (F-G) from severe HA patients (FVIII < 1%) without (D,F) and with (E,G) a high titer of inhibitor. Measurements are presented as means ± SEM. **P < .005; ***P < .0005. Ab, antibody; FEIBA, factor eight inhibitor bypassing activity.