C9orf72 and amyotrophic lateral sclerosis: It is well known that mutations in several genes linked to ALS (e.g., Tar DNA binding protein gene (TARDBP) which encodes for TDP-43 6, fused in sarcoma (FUS) 39, and the C9 open-reading frame 72 genes (C9orf72) 7, 8) impair axonal transport and alter mitochondrial function and dynamics (fission/fusion and trafficking) 9, 10, 45, 46.