FLI1 and Ewing sarcoma: Specifically, immunohistochemical markers such as Desmin (a marker of rhabdomyoblastic differentiation), Myogenin (specific for skeletal muscle lineage), INI1 (loss of expression observed in rhabdoid tumors and certain SRBCTs), FLI-1 (a sensitive marker for Ewing sarcoma), and NB84 (a marker for neuroblastoma) were not assessed.