The ADC changes after NTX treatment were also correlated with the histological findings including significantly decreased cellularity and cell proliferation in the NTX group of the TMZ-resistant GBM model compared with the control group (Fig. 4), which are, in particular, supported by the decreased APE-1 expression level and the increased TUNEL-positive cells, well correlated with the in vitro results in our study (Figs 2 and 4 and Supplementary Fig. S2). Here, APEX1 is linked to glioblastoma.