RAN and amyotrophic lateral sclerosis: Ranbp2 plays a central role in the homeostasis of the Ran GTPase cycle (Patil et al., 2014; Cho et al., 2010; Villa Braslavsky et al., 2000; Vetter et al., 1999; Hamada et al., 2011; Ritterhoff et al., 2016) and controls the proteostasis of ALS-causing substrates, such hnRNPA2B1 (Cho et al., 2015b, 2014).