C9orf72 and amyotrophic lateral sclerosis: In addition, pTDP-43 aggregates colocalized with GR repeat proteins in OrgALS cerebral organoids injected with protein extracts from C9orf72-ALS, suggesting that GR repeat protein spread and recruited the formation of TDP-43 pathology in cerebral organoids that do not have the C9orf72 gene expansion (S4B Fig).