C9orf72 and amyotrophic lateral sclerosis: Moreover, the binding of an RNA, derived from a hexanucleotide repeat expansion (HRE), (GGGGCC)n, in the noncoding region of C9orf72, with NCL, could be a culprit behind amyotrophic lateral sclerosis and frontotemporal dementia via the aggravation of nucleolar stress [30,31].