The vast majority of ES cases are characterized by the t(11;22)(q24;q12) chromosomal translocation, leading to the fusion of a 5’ segment of the EWSR1 gene (Ewing Sarcoma breakpoint region 1) and a 3′ portion of the FLI1 (Friend leukemia virus integration site 1). Here, EWSR1 is linked to Ewing sarcoma.