Aberrant cysteine modifications, resulting in proteostasis loss, are found in many proteins involved in ALS pathogenesis, including SOD1, TDP43, peroxiredoxins (PRXs), protein disulfide isomerases (PDIs), AMP kinase, and fibroblast growth factor 2 (FGF2). This evidence concerns the gene P4HB and amyotrophic lateral sclerosis.