KU-0060648 is primarily used in research settings to study its effects on DNA repair mechanisms and cancer cell behavior. It functions as a potent inhibitor of DNA-dependent protein kinase (DNA-PK), which plays a crucial role in the non-homologous end joining (NHEJ) pathway of DNA repair. By inhibiting DNA-PK, KU-0060648 is utilized to investigate how disrupting this pathway affects cancer cells, particularly in enhancing their sensitivity to radiation and chemotherapy. This makes it a valuable tool in exploring potential strategies for improving cancer treatment efficacy. Additionally, it is used in preclinical studies to understand the broader implications of DNA repair inhibition in cellular responses to DNA damage.