Inhibition of GPVI causes dose-dependent reduction in platelet PS exposure but not in total surface coverage. Blood was treated with 10B12 at 10-300 μg/mL (white symbols) or 1C3 at 100 μg/mL (black symbols). Total surface coverage of platelets (squares) and surface coverage of OG488-labeled annexin V binding platelets (circles) were measured after 4 minutes of perfusion. Data represent mean ± SE from 3 to 17 experiments performed on the blood of 3 donors. **Significant difference from 10B12 treatment (P < .001) and from control (P < .05).