We obtained brain tissue samples from ten ALS and FTD C9orf72 repeat carriers (C9orf72+), nine ALS and FTD patients carrying a non-pathogenic C9orf72 repeat (C9orf72−), and nine C9orf72− disease controls (clinical information in online resource, Table 2). This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.