Factor VIII titration at 5 pmol/L factor VIIa⋅TF. Thrombin formation was initiated by 5 pmol/L factor VIIa⋅TF in the presence of 0% (solid stars), 3.125% (open squares), 6.25% (solid triangles), 12.5% (open diamonds), 25% (solid squares), 50% (open stars), and 100% (solid circles) of the normal plasma concentration of factor VIII. Thrombin generation is also shown for reactions initiated by 1 pmol/L factor VIIa⋅TF in the absence (open triangles) or presence of factor VIII (100%, open circles). Data points are the mean of two experiments.