FEN1-IN-4 is primarily utilized in biochemical research as a specific inhibitor targeting the Flap Endonuclease 1 (FEN1) enzyme. This enzyme plays a critical role in DNA replication and repair processes, making it a key focus in studies related to cancer biology and therapeutic development. Researchers employ FEN1-IN-4 to investigate the mechanisms of DNA repair pathways and to explore its potential in sensitizing cancer cells to treatments like chemotherapy and radiation. By inhibiting FEN1, this compound helps in understanding the enzyme's role in maintaining genomic stability and its implications in diseases characterized by DNA repair defects. Additionally, it serves as a valuable tool in drug discovery efforts aimed at developing novel anticancer therapies that target DNA repair mechanisms.