C9orf72 and amyotrophic lateral sclerosis: ALS-associated mutations in Zn/Cu Superoxide Dismutase 1 (SOD1), TDP-43, Fused in Sarcoma (FUS), and the chromosome 9 opening reading frame 72 (C9orf72) disrupt mitochondrial OXPHOS [403], leading to defects in ETC complexes I and IV, further impairing ATP production [403].