Competing interests: MB reports grants from the National Institutes of Health (R01-NS105479) and the Muscular Dystrophy Association; as well as consulting fees from Alector, Annexon, Biogen, Denali, Novartis, Orphazyme, Sanofi and UniQure. The University of Miami has licensed intellectual property to Biogen to support design of the ATLAS study. SAG reports grants from National Institutes of Health, Centers for Disease Control and Prevention (CDC/ATSDR), and the ALS Association, as well as consulting fees from Structure Films. He is listed as inventor on patent held by University of Michigan for the treatment of ALS and reports the participation on a Data Safety Monitoring Board or Advisory Board for Watermark. KAS reports consulting fees from the ALS Association. ELF reports grants from the National Institutes of Health, Centers for Disease Control and Prevention (CDC/ATSDR), the Novo Nordisk Foundation, and the Juvenile Diabetes Research Foundation. She is named as inventor on a patent held by University of Michigan titled 'Methods For Treating Amyotrophic Lateral Sclerosis' for treating ALS using JAK/STAT inhibitors and reports multiple positions on Data Safety Monitoring Boards, Advisory Boards or or other boards, as well as multiple editorial positions. MW reports grants from the National Institutes of Health and the Centers for Disease Control and Prevention, as well as consulting fees from the Spaulding Rehabilitation. He additionally reports membership on a Data Safety Monitoring Board or Advisory Board for Biogen, a leadership role for the International Society for Environmental Epidemiology, and an editorial position with Springer. ET reports a position in the Pa Rare Disease Task Force. KDD reports the support of the preparation of this manuscript from the ALS Association and the ASTDR’s National ALS Registry. NMT reports the support of the preparation of this manuscript from the ALS Association and the ASTDR’s National ALS Registry. AA-C reports consultancies or advisory boards for Amylyx, Apellis, Biogen, Brainstorm, Cytokinetics, GenieUs, GSK, Lilly, Mitsubishi Tanabe Pharma, Novartis, OrionPharma, Quralis and Wave Pharmaceuticals.