To test for the functional significance of KCa3.1 on clonogenic survival of DMEM cultured and stem-cell enriched (NSC culture) glioma cells after irradiation (0–8 Gy) and/or chemotherapy, we applied the KCa3.1 blocker TRAM-34 (0 or 5 μM) in combination with temozolomide (0 or 30 μM). This evidence concerns the gene KCNN4 and central nervous system cancer.