Flow cytometric determination of TFPI. HUVECs treated with staurosporine (left panels) or kept in suspension with serum-deprivation (right panels) for 2, 4, and 8 hours were harvested, washed, and stained with a rabbit antihuman TFPI antibody, followed by an FITC-conjugated antirabbit MoAb. The M1-region is defined as the percentage of events below the control (all panels, right peak). The results of one representative experiment of three performed are shown.