C9orf72 and amyotrophic lateral sclerosis: For instance, in the ALS/FTD disease model, arginine-containing dipeptides, generated following the pathogenic expansion of a hexanucleotide repeat (G4C2) in C9orf72, have been observed to impact the dynamics of SGs, nucleoli, nuclear speckles, and Cajal bodies (Lee et al., 2016), and mutation in TDP-43 and FUS can influence properties of both SGs and other MLOs (Table 2).