IDO1-IN-34 is a selective IDO1 inhibitor with an IC50 of 0.093 µM. IDO1-IN-34 exhibits cytotoxicity against various cancer cell lines. IDO1-IN-34 inhibits the kynurenine (kynurenine) pathway and activates IL-2. IDO1-IN-34 induces cell apoptosis via the endogenous mitochondrial pathway, while increasing the levels of cytochrome c, caspase-3, caspase-9 and PARP-1. IDO1-IN-34 can be used for research on liver cancer, lung cancer, breast cancer, prostate cancer, colon cancer and leukemia[1].