GW3965 HCl is primarily used in research settings to study the role of liver X receptors (LXRs) in various biological processes. It acts as an LXR agonist, making it valuable for investigating lipid metabolism, cholesterol homeostasis, and inflammation. Researchers utilize it to explore potential therapeutic applications in diseases such as atherosclerosis, Alzheimer's disease, and diabetes. Additionally, it is employed in studies focusing on the regulation of gene expression involved in cholesterol efflux and reverse cholesterol transport. Its ability to modulate LXR activity also makes it a tool for understanding immune responses and cancer biology.