The oncogenic driver of the disease is an Ewing sarcoma breakpoint region 1/E26 (EWSR1-ETS) gene fusion leading to the expression of a potent, aberrantly cell reprograming transcription factor, most frequently EWS-FLI1 (Ewing sarcoma RNA binding protein-Friend leukemia virus integration site 1). The gene discussed is EWSR1; the disease is sarcoma.