Data shown as means ± standard errors of the mean from at least 2 independent experiments. Specific activity was determined by activated partial thromboplastin time–based clotting assay measurement of clotting activity relative to protein concentration. Kinetic values were determined for FX activation by intrinsic Xase assay using 0.25 nM of FVIIIa, 20 nM of FIXa, and 0-500 nM of FX in presence of 20 µM of phospholipids.