PROM1 and glioblastoma: Radiotherapy promotes autophagy, which prevents apop-tosis in CD133+ cells, becoming a major cause of drug resistance (Hsin et al., 2020) It was found that in the cells of methylated ASL, the ADI-PEG20 inhibited the growth of CD133+ GBM cells with the same efficiency as CD133-, suggesting that CD133+ cells do not impede the effectiveness of ADI-PEG20 treatment in vivo (Syed et al., 2013).