APC resistance of recombinant wild-type and mutant murine FV. Each point represents the average of the activity measured in conditioned media from three independent transfections. APC resistance assays were performed as described in the experimental procedures. APC was added to the reactions at t = 0. (◊), Wild-type FV; (▵), FV R305Q; (□), FV R504Q; (○), FV R305Q/R504Q.