EXT2 and glioblastoma: Consistently, CRISPR/Cas9-mediated EXT2 knockout (KO) in U-251MG and DD-T4 GBM models resulted in decreased basal survival and induced radiosensitization (Fig. 3E, Supplementary Fig. S5), whereas EXT2 overexpression led to increased platting efficiency and radioprotection in both cell models (Fig. 3F).