C9orf72 and amyotrophic lateral sclerosis: hnRNP A3 was identified as a component of some of the p62-positive and TDP-43-negative hippocampal inclusions seen in a subset of FTLD/ALS cases with the C9orf72 expansion; it was also shown to be a component of “RNA foci” and it has been suggested that it binds to the GGGGCC repeats in C9orf72 transcripts (Mori et al., 2013); however, its pathogenic role has not yet been determined.