The RT-PCR of the fusion products of the two most common Ewing sarcoma translocations t(11;22) EWSR1/FLI1 and t(21;22) ESWR1/ERG was negative; however, FISH analysis revealed the EWSR1 gene rearrangement (Figure 2(c)), confirming the diagnosis of Ewing sarcoma and suggesting the presence of one of the rare ES translocation types. This evidence concerns the gene EWSR1 and Ewing sarcoma.