Like other proteins of the FET family (FUS, EWSR1 and TAF15; Ewing’s sarcoma (EWS) and TAF15 (TATA-binding protein-associated factor), mutations in fused in sarcoma (FUS) are directly linked with protein aggregation in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia patients. The gene discussed is EWSR1; the disease is Ewing sarcoma.