ANXA5 and glioblastoma: Consistently, the Annexin V-FITC/PI double staining assay was performed to determine cell apoptosis, as expected, the results indicated that high-dose TMZ tended to induce cell apoptosis in TS-GBM cells, in contrast with TR-GBM cells (Fig. 1g), suggesting that TR-GBM cells were much more resistant to TMZ stimulation.