In this study, we examined CSF samples from patientscarrying SOD1, FUS, and TARDBP genemutations and C9ORF72 and ATXN2 expansion,where we already found an increased SeMet content in the CSF30 as well as the potential role of copper.4 Altogether, these findings showed a biologicalagreement on a possible mechanism of toxicity related to ALS, namely,an impairment of protective mechanisms against oxidative stress, prooxidant,mitochondrial damage, and lipid peroxidation. Here, ATXN2 is linked to amyotrophic lateral sclerosis.