It is important to note, however, that RNA foci formed by either C9ORF72‐S or C9ORF72‐AS do not correlate with the extent of neurodegeneration observed in ALS patients and are not determining factors of the clinico‐pathological variability observed in C9‐ALS cases (DeJesus‐Hernandez et al., 2017). This evidence concerns the gene C9 and amyotrophic lateral sclerosis.