FIG4 and neurodegenerative disease: Comparable accumulation of enlarged lysosomes causing the rapid development of severe brain degeneration was observed in both constitutive and neuron-specific Fig4 knock-out murine models (Ferguson et al. 2012), while in Drosophila Fig4 loss correlated with motility impairments and shorter lifespan (Bharadwaj et al. 2016; Kyotani et al. 2016).