For treatment of Ewing sarcoma xenografts we chose YK-4–279, described as inhibitor of EWS::FLI1/RNA helicase A interactions and microtubule polymerization, which has been reported to induce apoptosis in Ewing sarcoma cells and lead to growth reduction in a mouse xenograft model29,30. The gene discussed is EWSR1; the disease is Ewing sarcoma.