Considering the essential role of CRC in other developmental cancers driven by single transcriptional regulators (such as NMYC-driven neuroblastoma and PAX3-FOXO1-driven rhabdomyosarcoma) (22,23), we postulated that in Ewing sarcoma, a functional CRC apparatus might cooperate with EWS-FLI1 in the regulation of Ewing sarcoma transcriptome. This evidence concerns the gene PAX3 and neuroblastoma.