Used in cancer immunotherapy research, particularly as an inhibitor of the indoleamine 2,3-dioxygenase 1 (IDO1) enzyme. This inhibition helps restore T-cell activity and enhances the immune system's ability to recognize and attack tumor cells. It has shown promise in preclinical studies for treating solid tumors and is often investigated in combination with other immunotherapies like checkpoint inhibitors. Its analogue structure allows for improved metabolic stability and potency in modulating the tumor microenvironment.