C9orf72 and amyotrophic lateral sclerosis: Unexpectedly, immunostaining revealed strong colocalization of nuclear TDP-43 aggregates with hnRNP H, which has been linked to RNA toxicity in C9orf72 cases, and weak colocalization with hnRNP A1 previously implicated in ALS/FTD [30, 33] (Fig. 4d).