C9orf72 and amyotrophic lateral sclerosis: Cytoplasmic TDP-43 inclusions are one of the hallmark pathologies of C9orf72 ALS and FTD and have been reported in glial cells of C9orf72 ALS/FTD postmortem tissues (Al-Sarraj et al., 2011; Cooper-Knock et al., 2012; Schipper et al., 2016).