Other ALS-related proteins such as SOD1 [160], FUS [145], UBQLN2 [161], and C9ORF72-derived dipeptide repeat (DPR) proteins [162,163], have been found within toxic aggregates which are positive for several proteasome components [164], while nonmutated forms of TDP-43, OPTN, and UBQLN2 have been observed in such ubiquitinated inclusions, further aggravating the disrupted cellular homeostasis in ALS. Here, OPTN is linked to amyotrophic lateral sclerosis.