The active metabolite of the alkylating prodrug cyclophosphamide, 4HC; the DNA intercalator and topoisomerase II inhibitor, doxorubicin; the topoisomerase II inhibitor, etoposide; the active metabolite of the topoisomerase I inhibitor irinotecan, SN-38; and the Beta-tubulin inhibitor, vincristine were chosen due to their role in first and second line treatment of ES. Here, TUBB is linked to Ewing sarcoma.