Antitumor activity on glioblastoma xenografts for control and experimental groups. Ionizing radiation alone (Rad) or combined with Temozolamide (Rad + Tmz), Mifepristone (Rad + Mife) or both (Rad + Tmz + Mife). Each point represents the average ± SEM of four to five animals. (*) indicates a significant difference (p < 0.05) between the control and experimental groups; (†) and (‡) represent a significant difference between Rad + Tmz + Mife vs. Rad and Rad + Tmz + Mife vs. Rad + Tmz, respectively. (#) indicates a significant difference between Rad vs. Rad + Mife.