ALS-associated mutant forms of TDP-43 and FUS are known to form abnormal cytosolic aggregates [15], [16], [35], [39]–[41], and high-level overexpression of either wild-type or mutant TDP-43 is neurotoxic in mice, zebra fish and Drosophila[42]–[47]. Here, FUS is linked to amyotrophic lateral sclerosis.