RAD51-IN-17 is a potent and selective inhibitor of the RAD51 protein, which plays a central role in homologous recombination (HR), a key DNA repair pathway in cells. By inhibiting RAD51, this compound disrupts the repair of DNA double-strand breaks, making it particularly useful in cancer research, especially in tumors that rely heavily on HR for DNA repair. One major application is in combination with DNA-damaging agents such as ionizing radiation or chemotherapeutic drugs like PARP inhibitors. RAD51-IN-17 sensitizes cancer cells to these treatments by preventing effective DNA repair, leading to increased cell death. This effect is especially pronounced in cancers with underlying DNA repair deficiencies, such as those with BRCA mutations. It is also used as a research tool to study DNA repair mechanisms and genomic instability. Due to its ability to impair HR, RAD51-IN-17 helps scientists investigate synthetic lethality and identify new therapeutic strategies for resistant cancers. Its selectivity makes it a promising candidate for developing targeted therapies with fewer off-target effects.