CDK inhibitors such as THZ1, NVP-2 and THZ531 that inhibit CDK7, CDK9, CDK12 and CDK13, respectively, have been shown to downregulate SE-related oncogene expression and promote DNA damage response gene loss in chordoma and acute T-lymphoblastic leukaemia cells, respectively (185, 186, 188). This evidence concerns the gene CDK9 and chordoma.