The concentration ratio of rFVIIa to FVII regulates thrombin and FXa-generation responses to rFVIIa. (A) Comparison of experimental TG peak height data (dotted lines, n = 8) and FXa-generation model simulations (lines). Simulation output is the integral of FXa generation (total FXa generation after 40 minutes) and is proportional to TG peak heights (supplemental Figure 6B). Activation was with 1pM TF (Innovin). Experimental data are normalized to an internal control (signal at 6nM rFVIIa without FVII) to reduce effects of variability on dose-dependent curves. (B) The reactions modeled in our FXa-generation theoretical simulations. These reactions are the minimum set needed to predict our TG experimental data.