C9orf72 and amyotrophic lateral sclerosis: One of the major ribonucleoproteins bound, nucleolin, has been found to be bound and aberrantly localized due to binding with RNA–DNA R-loops in individuals with C9orf72 mediated ALS, negatively affecting the nucleolus of the cell by causing an aberrant distribution of nucleolin and ultimately nucleolar stress due to the processing of ribosomal RNA and accumulation of untranslated mRNA (Haeusler et al., 2014).