C9orf72 and amyotrophic lateral sclerosis: Given that c9orf72 FTLD Purkinje cells carry slightly less cytoplasmic poly(GA) and slightly more nuclear poly(GA) than c9orf72 ALS cases (Fig. 8b), it is expected that, overall, c9orf72 FTLD poly(GA)+ neurons will have more cavities than c9orf72 ALS.