SOD1 and amyotrophic lateral sclerosis: Varied morphological changes have been observed in the early stages of ALS disease within motor neurons (MNs) from transgenic mouse models with SOD1 [30,31,32], FUS [33], and TDP-43 [34,35] mutations; cortical neurons from the C9orf72 mouse model [36]; and muscle samples from ALS patients [24].