1. From the Division of Hematology Oncology, Massachusetts General Hospital (H.A.-S.) and the Dana–Farber/Boston Children’s Cancer and Blood Disorders Center (R.F.G.), Harvard Medical School, Boston, and Agios Pharmaceuticals, Cambridge (M.P.J., E.Z., R.X., P.H., V.B., S.G.) — all in Massachusetts; Unité des Maladies Génétiques du Globule Rouge, Centre Hospitalier Universitaire Henri Mondor, Créteil, France (F.G.); the Department of Hematology, Copenhagen University Hospital, Rigshospitalet, Copenhagen (A.G...