NS-398 is widely used in scientific research as a selective inhibitor of cyclooxygenase-2 (COX-2), an enzyme involved in inflammation and pain. Its primary application lies in studying the role of COX-2 in cellular pathways, particularly in models of inflammation, cancer, and neurodegenerative diseases. Researchers use NS-398 to suppress prostaglandin production selectively, helping to differentiate the effects of COX-2 from COX-1 in various biological systems. It has also been employed in cancer research due to its ability to induce apoptosis and inhibit proliferation in certain tumor cell lines. Due to its specificity, NS-398 serves as a valuable tool compound in pharmacological studies aiming to develop safer anti-inflammatory drugs with reduced gastrointestinal side effects.