SOD1 and amyotrophic lateral sclerosis: Finally, although there is relatively little evidence of Ran-GTPase cycle dysfunction in SOD1-ALS and FUS-ALS, cytoplasmic mislocalization of RanGAP has been described in spinal motor neurons of SOD1-G93A mice (Shang et al., 2017) and iPSC-derived neurons from FUS-ALS cases display increased cytoplasmic Ran-GTPase (Lin et al., 2021).