SOD1 and sarcoma: Most ALS cases are sporadic (sALS), and only approximately 5–10% of cases have a genetic background and are related to mutations in more than 20 genes, including the genes encoding SOD1 (superoxide dismutase 1), the RNA/DNA-binding proteins TDP-43 (TAR DNA-binding protein 43) and FUS/TLS (fused in sarcoma/translocated in liposarcoma), and C9orf72 (chromosome 9 open reading frame 72).