So, to assess whether RAD51 was involved in the radiosensitizing effect induced by iPA, we evaluated RAD51 levels by western blot and its ability to form foci by immunofluorescence in glioblastoma cells pretreated with iPA 1 μM plus irradiation at 4-Gy in comparison to untreated cells or cells treated with iPA or IR alone. Here, RAD51 is linked to glioblastoma.