AS-252424 is primarily used as a selective inhibitor of DNA-dependent protein kinase (DNA-PK), an enzyme involved in the repair of DNA double-strand breaks. Its main application lies in cancer research, particularly in studies aimed at enhancing the effectiveness of radiotherapy and DNA-damaging chemotherapeutic agents. By inhibiting DNA-PK, AS-252424 prevents efficient repair of tumor cell DNA after treatment with radiation or certain drugs, thereby increasing cancer cell death. It is widely used in preclinical studies to investigate mechanisms of DNA repair and to develop strategies for overcoming resistance to conventional cancer therapies. Its role as a research tool helps identify potential combination therapies that exploit genomic instability in tumor cells.