Accelerated thrombus formation in Cdc42^−/− mice. (A-C) Mesenteric arterioles were injured with FeCl₃ and adhesion, and thrombus formation of fluorescently labeled platelets was monitored in vivo by fluorescence microscopy. (A) Time to appearance of first thrombus and (B) interval between start of thrombus formation and vessel occlusion are shown. Each symbol represents 1 animal. (C) Representative images are depicted. Scale bar equals 50 μm. White asterisks indicate occlusion of the vessel.