Impaired hemostasis and thrombus formation in fII^MZ animals. (A) In a standard tail bleeding time analysis, fII^WT animals all achieved hemostasis, whereas no fII^MZ mice had cessation of bleeding during the 10-minute window of evaluation. In ferric chloride mesenteric arteriole injury, fII^WT animals developed occlusive thrombi (B). However, although fII^MZ mice formed platelet aggregates, these were unstable and embolized, frequently without progression to occlusion of the vessel (C). FII^MZ animals also exhibited a prolonged time to first thrombus formation (D) and prolonged time to occlusion (E).