1. From the Center for Interdisciplinary Cardiovascular Sciences (M.A.R., N.M., J.D.H., C.G., S.G., I.Y., T.F., M.A., E.A.) and Center for Excellence in Vascular Biology (M.A., E.A.), Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA; and Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD (H.S.).