Thrombin generation on 200 μmol/L PCPS at varying prothrombin and AT-III concentrations in the absence of protein C pathway. Thrombin generation was initiated by 5 pmol/L factor VIIa-TF in the presence of all proteins at their mean plasma concentrations (▪), in the presence of prothrombin at 150% and AT-III at 50% of mean plasma concentrations (•), in the presence of prothrombin at 50% and AT-III at 150% of mean plasma concentrations (▴), in the presence of prothrombin at 125% and AT-III at 75% of mean plasma concentrations (⧫), and in the presence of prothrombin at 75% and AT-III at 125% of mean plasma concentrations (□). Factors V, VIII, IX, and X and TFPI were present at mean plasma concentrations in all experiments.