A phase II trial of the immunoglobulin G1 monoclonal antibody cixutumumab and mammalian target of rapamycin inhibitor temsirolimus demonstrated a positive response, in which 35% (7/20) of Ewing sarcoma patients responded with stable disease of more than 5 months, and tumor regression was reported in 29% of patients.29 Moreover, profiling of 113 patients with Ewing sarcoma revealed secondary ERF and FGFR1 alterations with a prevalence of 7% and 3%, respectively.30 Future trials might address these alterations pharmacologically to improve treatment lines and overall survival. Here, ERF is linked to Ewing sarcoma.