C9orf72 and amyotrophic lateral sclerosis: Studies in postmortem tissues have given variable results, with one study describing irregular RanGAP labeling of the nuclear envelope in cortical motor neurons in C9orf72-ALS cases, whereas another study, using a larger cohort, failed to find any abnormalities of RanGAP labeling in cortical or spinal motor neurons of C9orf72 and sALS cases (Saberi et al., 2018).