EWSR1 and sarcoma: ES is a translocation driven sarcoma; t(11,22)(q24;q12) results in the formation of the EWSR1-FLI1 proto-oncogene (FLI1) fusion gene in 85% of cases; t(21,22)(q22;q12) in the EWSR1-ETS transcription factor ERG (ERG) fusion gene in 10%; and the remaining 5% of cases are characterised by other translocations all resulting in a fusion gene containing a portion of the EWSR1 gene (35,36).