Thrombin generation in fXII-deficient plasma. Thrombin generation was initiated by addition of Ca²⁺ and (A) 0.23 pM TF or (B) 5 nM (1 and 2) or 50 nM (3 and 4) α-thrombin. Reactions were run in the absence (1 and 3) or presence (2 and 4) of 50 nM O1A6. (C) Thrombin generation initiated with Ca²⁺ and 1 nM fXIIa in the presence of (1) vehicle, (2) 50 μg/mL CTI, or (3) 50 nM 14E11. (D) Thrombin generation initiated with Ca²⁺ and 5 nM α-thrombin (1-3) or no initiator (4). Reactions were run with (1) vehicle, (2) 50 nM O1A6, or (3) 50 nM 14E11.