RI-1 is primarily used in scientific research, particularly in the field of DNA repair studies. It is known to inhibit the activity of the Mre11-Rad50-Nbs1 (MRN) complex, which plays a critical role in the cellular response to DNA double-strand breaks. By inhibiting this complex, RI-1 helps researchers understand the mechanisms of DNA repair pathways, including homologous recombination. This makes it a valuable tool in studying cancer biology, as defects in DNA repair mechanisms are often associated with tumor development and resistance to treatments like chemotherapy and radiation. Additionally, RI-1 is used to explore potential therapeutic strategies targeting DNA repair processes in various diseases.