In addition, mutations in the endo-lysosomal trafficking machinery have been implicated in neurodegenerative disorders including ALS and FTD (CHMP2B, FIG4, VAPB, and VCP) (Yang et al., 2001; Parkinson et al., 2006; Johnson et al., 2010; Maruyama et al., 2010) and defects in retrograde trafficking increase the risk for Parkinson's disease (VPS35) (Zimprich et al., 2011). Here, FIG4 is linked to amyotrophic lateral sclerosis.