The identification of the DNA/RNA-binding protein TDP-43 as a component of abnormal, cytoplasmic inclusions in sporadic ALS patients2 and the later discovery of ALS-causing mutations in the TDP-43 gene (TARDBP)3 led to the identification of causal mutations in the gene encoding the related protein FUsed in Sarcoma (FUS)4, 5. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.