The authors thank Dr. A. Vasanji, Shiyang Wang, and Jenna Saraniti for assistance with image analyses, David Hellard for performing the blood pressure measurements, Dr. Y.Shchurina for the plasminogen analyses, Drs. Lindsey Burrage and Jonathan Smith for helpful discussions, and Robin Lewis for assistance with manuscript preparation. This study was supported by grants from NIH, HL17964, HL65204, HL078701 (JHP), T32 HL07914 (AS), and RR12305 (JHN).