There are currently two DNA-PK inhibitors (MSC2490484A: DNA-PK inhibitor, trials NCT02316197 and NCT02516813; CC-115: dual DNA-PK and TOR kinase inhibitor, trial NCT01353625) undergoing testing in Phase I clinical trials in adult patients, including those with Ewing sarcoma, as single agents and for MSC2490484A also as a radio-/chemo-sensitizing agent. The gene discussed is PRKDC; the disease is Ewing sarcoma.