These tumors are recognized as resistant to conventional X-RT, necessitating higher doses to achieve sufficient LC rates, In vitro data reported that the radioresistance of chordoma cells is associated with the ataxia-telangiectasia mutated (ATM)/ATM and Rad3-related (ATR) pathway, in which RAD51 serves as an important downstream effector.63 Here, ATM is linked to chordoma.