Several studies suggest possible defects in mitochondrial dynamics in models of ALS, regardless of the causative mutation (Menzies et al, 2002; Ehinger et al, 2015; Tafuri et al, 2015; Sharma et al, 2016). SOD1 resides in the mitochondrial intermembrane space, and abnormal mitochondrial morphology and cristae ultrastructure have been observed in mutant SOD1 mice and in ALS patient samples, predominantly in the spinal cord (De Vos et al, 2007; Song, Song et al, 2013). Mutant SOD1G93A affects mitochondrial dynamics, resulting in a significant decrease in mitochondrial length and an accumulation of round fragmented mitochondria (Tafuri et al, 2015). Abnormal mitochondrial dynamics was also recently observed in skeletal muscle of the SOD1 G93A mice (Luo et al, 2013), together indicating the importance of mitochondrial dynamics in ALS.