Thrombin generation assay. Thrombin generation was measured in (A) human HB plasma supplemented with 0.1 nM of FXa or (B) with FXa supplemented with 20 nM FVa in the presence of 2.0 pM TF/4 µM phospholipid (reagent RB; Technoclone). Thrombin generation was initiated with CaCl₂, and a thrombin fluorogenic substrate as detailed in “Methods.” Each curve is representative of 3 independent experiments. NHP, normal human plasma.