Poly-GR has been shown to have toxic effects on ribosomal proteins, by co-localizing with various ribosomal proteins and binding translation initiation factors, including eIF3η, in murine models as well as post-mortem C9orf72 ALS brain tissue (Lee et al., 2016; Zhang et al., 2018). Here, C9orf72 is linked to amyotrophic lateral sclerosis.