The most common of these translocations is t [11; 22] (q24; q12), which is present in nearly 85% of cases of Ewing's sarcoma; this results in a tumourigenic fusion protein composed of the 5'- end of the EWS gene and 3'- end of the ETS family gene FLI1: This EWS-FLI1 fusion product has been reported in other malignant round cell tumours including neuroblastoma and mesenchymal chondrosarcoma [47,48]. This evidence concerns the gene EWSR1 and mesenchymal chondrosarcoma.