To link the FARSA dysfunction to C9orf72 associated ALS/FTD we evaluated the expression levels of Phe-rich proteins in lysates from post-mortem cerebellum from 12 ALS/FTD cases with presence of C9orf72 mutation and 12 TDP-43-positive ALS/FTD cases without a C9orf72 mutation (Fig. 4b, Supplementary Fig. 8c). Here, C9orf72 is linked to frontotemporal dementia.