C9orf72 and amyotrophic lateral sclerosis: Further studies have reported reduction of C9orf72 expression in induced pluripotent stem cell (iPSC) neurons and brain from C9-FTD/ALS patients (Almeida et al., 2013; Belzil et al., 2013; Donnelly et al., 2013; Waite et al., 2014).