Another study found that the PARP inhibitor talazoparib was able to reduce proliferation of glioblastoma (R633 and TG1) cells following low-LET photon irradiation, although these effects were exacerbated with high-LET CIRT (50 keV/μm), with particular effects on glioblastoma stem cells [54]. Here, PARP1 is linked to glioblastoma.