FUS and amyotrophic lateral sclerosis: A similar response was observed for ALS-associated mutant derivatives of both GFP-FUS (GFP-FUSR521C and GFP-FUSP525L; Fig S1A) and GFP-TDP-43 (GFP-TDP-43G298S and GFP-TDP-43M337V; Fig S1C), suggesting that ALS is not caused simply by a defect in the relocalisation of these proteins to nucleoli.