For example, we established an inducible mouse model in which (GR)80 is expressed in the brain at ~5–15% of the level in the brains of patients with C9ORF72 mutations and demonstrated that low-level poly(GR) expression alone can elicit several FTD/ALS-like behavioural and cellular phenotypes14. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.