CD274 and glioblastoma: Previous work indicated that PD-L1 activated autophagy to increase drug resistance in multiple cancers [29, 30], and targeting autophagy had been proved to be an effective strategy to improve TMZ-sensitivity in GBM [24, 25], but it was still unclear whether GSCs-derived PD-L1-ex contributed TMZ-resistance in GBM by activating PD-L1 mediated protective autophagy.