ARHGEF28 and amyotrophic lateral sclerosis: Previously, we described that RGNEF forms extensive NCIs that co-aggregate with TDP-43 in motor neurons of ALS patients11,12 and observed that RGNEF works as a survival factor under stress conditions in vitro.21 Also, we described that the N-terminal fragment of RGNEF, called NF242 (NH2-terminal fragment of 242 amino acids) in this study, is part of a high molecular weight complex with TDP-43 in vitro and that both co-localize under metabolic stress conditions.22