Inhibition of TF-dependent signaling by endogenous TFPI-1 in TNF-α–stimulated HUVECs. (A) TR3 induction by NAPc2 stabilized ternary complex (VIIa/Xa/C2) or by addition of VIIa (10 nM) and X (100 nM) in the presence of the indicated antibodies. The amount of Xa generated was determined after 10 minutes, prior to quenching of all free Xa with the specific inhibitor NAP5. Mean and SD (n = 3); asterisk indicates statistically different from control (P < .05, t test). (B) ERK1/2 phosphorylation in HUVECs stimulated for 10 minutes as in panel A was detected by Western blotting with phosphorylation-specific αP-ERK1/2. Equal amount of protein loading was confirmed by Western blotting with a nonphospho-specific α-ERK1/2 antibody.