conducted a systematic review of 22 chordoma cases involving progression from 2015 to 2022 and found that combination therapy with PD-1/PD-L1 antibodies and CTLA-4 monoclonal antibody was no more effective than monotherapy with PD-1/PD-L1 antibodies, but it was more toxic (54). This evidence concerns the gene CTLA4 and chordoma.