MPO and familial amyotrophic lateral sclerosis: ALS: Amyotrophic lateral sclerosis; DNA: deoxyribonucleic acid; RNA: ribonucleic acid; fALS: familial amyotrophic lateral sclerosis; FDA: Food and Drug Administration; SOD: superoxide dismutase; ASO: antisense oligonucleotides; MPO: myeloperoxidase