Unlike classical Ewing sarcoma, this tumour displays a characteristic FISH pattern with amplification at the 5′ end of the EWSR1 locus [17, 18] This is due to a genomic rearrangement that fuses the N-terminal transactivation domain of EWSR1 to the C-terminal DNA binding domain of NFATC2, and this fusion is often accompanied by amplification of the 5′ end of the EWSR1 locus. This evidence concerns the gene EWSR1 and Ewing sarcoma.