Mutations in PFN1 (profilin 1), identified in rare family cases of ALS, are associated with a deregulated RAB9-mediated autophagy pathway mediating mitochondrial clearance, which leads to a decrease in the number of mitochondria and ATP production in the cells of ALS patients and transfected cell lines [84]. Here, PFN1 is linked to amyotrophic lateral sclerosis.