1. From the Horae Gene Therapy Center, Department of Pediatrics, University of Massachusetts Medical School (UMMS) (C.M., G.G., M.B., T.R.F.), and the Department of Neurology, UMMS and UMass Memorial Medical Center (D.M.M.-Y., M.A.O., C.L.D., N.S.W., R.H.B.), Worcester, and the Healey Center for ALS, Department of Neurology (J.D.B., L.M.P., D.G., S.D.L., M.P.F., M.E.C.), and the C.S. Kubik Laboratory for Neuropathology (D.H.O., M.P.F.), Massachusetts General Hospital and Harvard Medical School, Boston.