Effect of protein C inhibitor on tissue factor-induced coagulation in the presence of TM. Normal plasma (A) and protein C–deficient plasma (B) were incubated with buffer (○), 80 (▪), or 160 (▴) nmol/L protein C inhibitor in the presence of TM (10 nmol/L). After incubation, recombinant tissue factor and calcium were added, and the change in turbidity was monitored at 405 nm.