KKI-5 is primarily utilized in biochemical research, particularly in the study of proteases and their inhibitors. It serves as a potent and selective inhibitor of the enzyme kallikrein-related peptidase 5 (KLK5), which is involved in various physiological and pathological processes, including skin desquamation, inflammation, and cancer progression. Researchers use KKI-5 to investigate the role of KLK5 in these processes, helping to elucidate its mechanisms and potential as a therapeutic target. Additionally, KKI-5 is employed in drug discovery efforts aimed at developing treatments for conditions where KLK5 activity is dysregulated, such as certain skin disorders and cancers. Its specificity makes it a valuable tool for understanding protease function and designing targeted therapies.