Explanation:Ewing sarcoma is characterized by a specific chromosomal translocation t(11;22)(q24;q12). This translocation results in fusion of the EWSR1 gene with the FLI1 transcription factor gene. The resulting fusion protein acts as an aberrant transcription factor driving oncogenesis. This molecular hallmark is seen in the majority of Ewing sarcoma cases and is useful diagnostically. Molecular testing helps differentiate Ewing sarcoma from other small round blue cell tumors. Identification of this genetic abnormality has also influenced targeted therapeutic research. Reference: Delattre O. "Gene Fusion with an ETS DNA-binding Domain Caused by Chromosome Translocation in Human Tumors." Nature, 1992.