Compared to control, fbg^–/– mice produce loosely packed thrombi with large pores and 7E9-treated mice produce small mural thrombi. Sections stained with hematoxylin and eosin from carotid artery segments obtained 30 minutes after FeCl₃-induced injury. Carotid sections from a control mouse (original magnification × 4), a fbg^–/– mouse (original magnifications × 10 and × 60), and a 7E9-treated mouse (original magnification × 4). Arrow shows unusually large pores observed only in thrombi of fbg^–/– animals.