Hematoxylin and eosin (H&E) staining (Fig. 4e), TUNEL (terminal-deoxynucleotidyl transferase mediated nick end labeling) assay (Fig. 4f, Supplementary Fig. 11a), and immunohistochemical staining of γ-H2A.X (Fig. 4g, Supplementary Fig. 11b) of tumor tissue sections further supported the enhanced efficacy as more severe levels of necrosis, DNA single-strand break (SSBs), and DSBs were found in Mb@Gd-NTs + RT group compared with Gd-NTs + RT group or Mb@NTs + RT group. Here, MB is linked to neoplasm.