Optimal conditions of zymogen inhibition. FVII-deficient plasma was supplemented with phospholipids (4μM), rFVIIa (6nM), and FVII (0, 10, or 100nM). Coagulation was activated with a 1pM concentration of either high-surface-density TF (1:4000 TF: phospholipid molar concentration ratio) or low surface-density TF (1:26 000). The presence of zymogen inhibition depends on the concentrations of FVII and rFVIIa and the strength of inhibition is related to the surface density of TF.