C9orf72 and amyotrophic lateral sclerosis: TDP-43 was previously found to interact with HTT carrying pathogenic CAG repeats.7 In addition, it has recently been shown that ATXN1 and ATXN2 influence the nucleocytoplasmic ratio of TDP-43, and that CAG tracks stimulate the cytoplasmic mis-localization of TDP-43 preceding aggregates.8-10 Furthermore, ATXN2 is a genetic modifier of C9orf72-disease, intermediate CAG repeats being associated with the risk to develop ALS.11