This FET-ETS fusion between a member of the FET family of genes, usually EWSR1 or FUS, and a member of the ETS (E26 transformation-specific or erythroblast transformation-specific) family of transcription factors, such as FLI1 or ERG, is a marker of Ewing sarcoma [7]. Here, EWSR1 is linked to Ewing sarcoma.