This is particularly important, as PARP1 inhibition (the most successful DDR‐targeting drug to date) may only confer a similar increased temozolomide sensitivity within cells that have MGMT promoter methylation [151], which represents ~ 40% of all patients diagnosed with glioblastoma and whose tumours are already intrinsically more sensitive to temozolomide. This evidence concerns the gene MGMT and glioblastoma.