1. From the Center for Regenerative Medicine (J.P.G., J.M.C., B.J.J., P.T.M., S.E.G., T.O., G.G., H.C.O.), Cardiovascular Research Center (R.W.M., D.J.M.), Division of Cardiology (D.J.M.), and Division of Thoracic Surgery, Department of Surgery (H.C.O.), Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA (J.P.G., B.J.J., P.T.M., S.E.G., G.G., H.C.O.); Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA (J.R.G., G.R.G.); and Harvard Stem Cell...