NU7026 is widely used in cancer research due to its ability to inhibit DNA-dependent protein kinase (DNA-PK), a key enzyme involved in the repair of DNA double-strand breaks. By blocking this repair pathway, NU7026 enhances the effectiveness of DNA-damaging agents such as ionizing radiation and certain chemotherapeutic drugs. It is commonly employed in studies aiming to overcome tumor resistance to radiotherapy and chemotherapy, particularly in cancers where DNA repair mechanisms contribute to treatment failure. Its application is primarily confined to preclinical research, where it serves as a tool compound to probe DNA repair pathways and to develop combination therapies that increase cancer cell sensitivity to genotoxic treatments.