EWSR1 and Ewing sarcoma: Having shown that KDM5A and PHF2 promote metastatic properties in Ewing sarcoma, and exert effects on metastasis in opposition to those of EWS/Fli1, we wondered whether inhibition of KDM5A or/and PHF2 could impair the biological properties of more metastatically potent EWS/Fli1low cells [10, 11, 13].