Schlafen family member 11 (SLFN11) is a transcriptional target of EWS-FLI1 and sensitizes Ewing sarcoma cells, as well as other cancer types, to a variety of DNA-damaging agents, including gemcitabine and additional RNR inhibitors (19, 21, 25, 39, 48, 49). Here, EWSR1 is linked to Ewing sarcoma.