Since the discovery of genetic mutations in the copper–zinc superoxide dismutase (Sod1) gene, other pathogenic mutations in more than 10 different genes have been discovered6, being mutations in Sod1, chromosome 9 open reading frame 72 (C9orf72), fused in sarcoma (Fus) and TAR DNA-binding protein 43 (Tardbp) the most prevalent. Here, SOD1 is linked to sarcoma.