Effects of anti-fXII antibodies on thrombin generation. Shown are the effects of 4 μM 9A2, 15H8, or vehicle (V) on thrombin generation in normal plasma triggered with (A) 1% v/v aPTT reagent or (B) 100 μg/mL type I collagen. No thrombin is generated in the absence of aPTT reagent or collagen. (C) Thrombin generation in fXII-deficient plasma supplemented with 5 nM fXIIa in the presence of 500 nM 9A2, 15H8, or vehicle (V). –XIIa indicates that no thrombin was generated in the absence of fXIIa.