Forrest et al. developed an IONP−based nanocarrier that could protect the efficient delivery of anti−Ape1 siRNA into brain cancer cells, enabling brain cancer to be sensitive to radiotherapy by knocking down the multifunctional DNA repair enzyme apurinuclease 1 (Ape1) and, thereby, increasing the antitumor effect and extending the survival of animals, synergizing with radiotherapy [109]. Here, APEX1 is linked to brain cancer.