SOD1 and amyotrophic lateral sclerosis: Since the initial discovery of copper–zinc superoxide dismutase (SOD1) as a causal gene for ALS, numerous genes such as TAR DNA-binding protein 43 (TDP-43), fused in sarcoma (FUS), TATA-binding protein-associated factor 15 (TAF15), and chromosome 9 open reading frame 72 (C9orf72), have been found to be associated with fALS and sALS [4,5,6,7,8,9,10].