The critical driver of Ewing sarcoma results from a chromosomal translocation that brings together the EWSR1 gene (or one of the other so-called FET genes) and one of several ETS transcription factors, most commonly FLI1 (EWS::FLI1, in ~85% Ewing sarcoma patients)3. This evidence concerns the gene EWSR1 and Ewing sarcoma.