C9orf72 and amyotrophic lateral sclerosis: Mutations in ALS-associated genes such as TDP-43, FUS, SOD1, C9orf72, and Sigma-1 receptor (Sigma-1R) can alter mitochondrial integrity and function (Smith et al., 2019; Shoshan-Barmatz et al., 2020; Dafinca et al., 2021; Wood et al., 2021).