Thrombotic occlusion times after photochemical injury of the carotid artery. HCII^+/+ or HCII^−/− mice were injected intravenously with saline (none) or purified rHCII (WT, R189H, or K173Q) 15 minutes before injection of rose bengal dye. The dose of rHCII was calculated to achieve a plasma concentration of 0.125 μM. The bars indicate the means plus or minus SD.