Thrombi are larger in PECAM-1–deficient mice. (A) Median thrombus integrated fluorescence (anti-CD41) (Ai) and area (μm²) (Aii) were calculated for thrombi formed in control (+/+) and PECAM-1–deficient (–/–) mice and are plotted against time for a duration of 120 seconds following thrombus initiation (control: n = 14 thrombi; PECAM-1–deficient: n = 20 thrombi). (B) As a measure of thrombus stability, the durations for which thrombi remained above 50% of maximal integrated fluorescence (anti-CD41) (Bi) and thrombus area (Bii) were calculated, and mean values ± SEM are shown. (Bi) *P = .04; (Bii) *P = .02.