Expanded hexanucleotide repeats in the non-coding region of C9orf72 gene leads to a decrease in the levels of endogenous C9orf72 protein (DeJesus-Hernandez et al., 2011; Donnelly et al., 2013; Belzil et al., 2013) alongside generating flawed nuclear RNA foci (Wojciechowska & Krzyzosiak, 2011; Van Blitterswijk, DeJesus-Hernandez & Rademakers, 2012), suggesting both gain of function as well as loss of function disease mechanism for C9orf72 in ALS (Haeusler, Donnelly & Rothstein, 2016). Here, C9orf72 is linked to amyotrophic lateral sclerosis.