1. From the Washington University School of Medicine, St. Louis (T.M., R.C.B., A.P.); the Healey Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston (M.C., N.A.), and Biogen, Cambridge (A.S., H.R., D.G., H.H., A.M., I.N., I.C., L.F., S.F., T.A.F.) — both in Massachusetts; the Sheffield Institute for Translational Neuroscience, University of Sheffield, and NIHR Sheffield Biomedical Research Centre and Clinical Research Facility, University of Sheffield and Sheffield Teaching...