1. Massachusetts General Hospital, Boston, Massachusetts (S.D.C., Y.C.)
2. University of Michigan, Ann Arbor, Michigan (P.C., J.J., R.M.)
3. Stanford University School of Medicine, Stanford, California (M.B., I.T., S.K.P.)
4. Erasmus University Medical Center, Rotterdam, the Netherlands (K.T., E.F.B., H.J.D.)
5. Massachusetts General Hospital, Boston, Massachusetts, and Broad Institute, Cambridge, Massachusetts (D.F.S.)
6. Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (C.Y.K.)