C9orf72 and amyotrophic lateral sclerosis: The C9orf72 pathology is characterized by hexanucleotide repeat expansion in the first intron of the C9orf72 gene, a common ALS-FTD mutation that results in the formation of nuclear RNA foci, dipeptide repeat protein inclusions and TDP43 aggregates and is the most frequent reported genetic cause of ALS-FTD (Renton et al., 2011).