IDO-IN-12 is primarily used in research settings to study the role of indoleamine 2,3-dioxygenase (IDO) in various biological processes. It is an inhibitor of IDO, an enzyme that plays a key role in immune regulation and tryptophan metabolism. Researchers utilize IDO-IN-12 to investigate its potential in modulating immune responses, particularly in the context of cancer immunotherapy. By blocking IDO activity, it may help enhance the immune system's ability to recognize and attack tumor cells. Additionally, it is employed in studies exploring its effects on autoimmune diseases and chronic inflammatory conditions, where IDO overexpression is often observed. Its application extends to preclinical models to evaluate therapeutic efficacy and safety.