Our prior studies identified a novel disease-promoting epigenetic axis in the pediatric sarcomas Ewing Sarcoma, FN-RMS, and FP-RMS, involving the chromatin factor KDM3A, a member of the Jumonji-domain histone demethylase family, and the transcription factor ETS1, a member of the ETS transcription factor family [13–15]. Here, KDM3A is linked to Ewing sarcoma.