Although the familial forms of the disease can be caused by mutation of ∼20 genes, including Cu/Zn superoxide dismutase (SOD1) (1) and trans-activation response DNA-binding protein (TARDBP, encoding the protein TDP-43) (2), pathologically aggregated WT TDP-43 inclusions are a hallmark of all non-SOD1/fused in sarcoma–associated ALS (3, 4). This evidence concerns the gene SOD1 and sarcoma.