RAB5A and amyotrophic lateral sclerosis: Coinciding with its role in lysosomal function, both rodent and iPSC-derived neuronal models of UBQLN2-ALS reported enlarged LAMP1-positive vesicles that colocalized with UBQLN2 aggregates and the endosomal protein Rab5 was found to be a modifier of this pathology [217,218].