ACAT-IN-9 is primarily utilized in research settings to study the inhibition of acyl-CoA:cholesterol acyltransferase (ACAT) enzymes. These enzymes play a critical role in cholesterol esterification, a process essential for cholesterol absorption and storage in cells. By inhibiting ACAT, this compound helps researchers investigate the mechanisms of cholesterol metabolism and its impact on conditions like atherosclerosis and hypercholesterolemia. It is also used in preclinical studies to explore potential therapeutic strategies for managing lipid-related disorders, including cardiovascular diseases. Additionally, ACAT-IN-9 serves as a tool to understand the role of ACAT in foam cell formation, a key event in the development of arterial plaques. Its application extends to drug discovery, where it aids in identifying and optimizing compounds targeting ACAT for therapeutic purposes.