C9orf72 and amyotrophic lateral sclerosis: In ALS, mutations in SOD1, TAR DNA-binding protein 43 (TDP-43), and guanine nucleotide exchange factor C9orf72 (C9orf72) affect mitochondrial bioenergetics and dynamics, with C9orf72-derived poly-GR dipeptides promoting degradation of mitochondrial ATP synthase F(1) complex subunit alpha (ATP5A1) [62,63,64,65].