LY2608204 is a selective inhibitor of DNA-dependent protein kinase (DNA-PK), an enzyme involved in the repair of DNA double-strand breaks, particularly through the non-homologous end joining (NHEJ) pathway. Due to its inhibitory action, LY2608204 is primarily used in cancer research to sensitize tumor cells to DNA-damaging treatments such as ionizing radiation and certain chemotherapeutic agents. By impairing the cell’s ability to repair DNA damage, this compound enhances the cytotoxic effects of radiotherapy and genotoxic drugs in preclinical models. It is especially studied in combination therapies targeting cancers with high rates of DNA repair activity, where resistance to conventional treatments is a challenge. Its application remains experimental, focused on understanding DNA repair mechanisms and developing strategies to overcome treatment resistance in oncology.