Furthermore, the study showed that repeat expansion RNAs, including ALS/FTD ‘C9 repeats, increase active/phosphorylated PKR (p-PKR) levels in vitro and in vivo in mice, while higher p-PKR levels were detected in hippocampal tissue from C9orf72 ALS patients [74]. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.