However, we measured the expression of poly-GA in spinal cord of 4–6-month-old GA-CFP mice and motor cortex of C9orf72 ALS/FTD patients with abundant poly-GA pathology by immunoassay (Fig. S3d) and additionally counted the frequency of neuronal poly-GA inclusions in the most affected regions of GA-CFP mice and the neocortex of C9orf72 patients (Fig. S3e, f). Here, AGA is linked to amyotrophic lateral sclerosis.