EWSR1 and Ewing sarcoma: Despite their similarities in histologic features, ES differs from the other sarcomas in its clinical aggressiveness and molecular profile, which consists of a specific translocation involving FLI1 on chromosome 11q24 and breakpoint region 1 (EWSR1) on chromosome 22; most notably t(11;22)(q24;q12), producing the EWSR1-FLI1 fusion transcript protein [3,4].