TF activates FIX in thrombin-inhibited wild-type and FXI^−/−mice. Plasma levels of FIXa-AT complexes were quantified in dabigatran-pretreated wild-type (WT) (A) or FXI^−/− (B) mice, administered either vehicle control or TF (n = 6-10 per group). A significant increase in plasma FIXa-AT complexes was observed on administration of TF in both WT and FXI^−/− mice. Data are presented as individual values with means ± 95% confidence intervals. *P < .0001; **P < .05; unpaired Student t test.