IACS-8968 (S-enantiomer) is primarily used in research and therapeutic development as an inhibitor of IDO (indoleamine 2,3-dioxygenase) and TDO (tryptophan 2,3-dioxygenase) enzymes. These enzymes play a critical role in immune suppression by metabolizing tryptophan into kynurenine, which inhibits T-cell activation and promotes tumor immune evasion. By blocking IDO and TDO, this compound enhances immune responses, making it a promising candidate for cancer immunotherapy. It is particularly studied in combination with other immunotherapies to improve their efficacy in treating various cancers. Additionally, its S-enantiomer form is specifically targeted for its optimized potency and selectivity in preclinical studies.