Type 1 involves fusion of exon 7 of EWS with exon 6 of FLI1 and is found in 80% of the ES cases, while type 2 fusion includes exon 7 of EWS with exon 5 of FLI1 and is reported in about 15% of ES cases [43]. The gene discussed is EWSR1; the disease is Ewing sarcoma.