Prothrombin titration on 200 μmol/L PCPS in a coagulation protein activation experiment in the absence of protein C pathway. Thrombin generation was initiated by 5 pmol/L factor VIIa-TF in the presence of prothrombin at 150% (•), 125% (⧫), 100% (▪), 75% (□), and 50% (▴) of its mean plasma concentration. All other proteins were present at mean plasma concentrations.