EWSR1 and Ewing sarcoma: Ewing’s sarcoma is a malignant bone tumour in which 85% of patients harbour a gene translocation involving the Ewing’s sarcoma breakpoint region 1 (EWS) gene fused to the Friend leukaemia virus integration site 1 (FLI1) gene: EWS-FLI1 t(11;22) [1, 2].