Inhibition of thrombin generation by TFPI single-point variants in TFPI-depleted plasma. Thrombin generation was measured in TFPI-depleted plasma supplemented with 4μM phospholipids, 1pM TF (Dade Innovin), and 0.25nM TFPI in concentrated conditioned medium in the presence or absence of 2.8μM antibodies against protein S. The inhibition of thrombin generation by WT TFPI (A) was compared with TFPI D194Q (B), TFPI R195Q (C), TFPI R199Q (D), TFPI E226Q (E), TFPI E234Q (F), and TFPI R237Q (G). Representative experiments are shown (n = 3). WT TFPI, TFPI R199Q, and TFPI E226Q were titrated in the absence of antibodies against protein S and the peak thrombin was plotted against the TFPI concentration. Means ± SD (n = 3) are shown in panel H.