FUS and amyotrophic lateral sclerosis: However, the majority of ALS-associated mutations identified in FUS are localized to the N-terminal RGG-rich region (residues 165–276) or a short stretch (residues 495–526) of the C-terminal RGG-rich region (residues 449–526) which contains the FUS NLS (Abel et al., 2013); only one ALS-associated mutation (G156E) has been identified in the PrLD.