IDO1-IN-19 (Compound 17) is an orally active IDO1 inhibitor with an IC 50 of CYP2C9 of 8.64 μM. IDO1-IN-19 also acts funciton on cardiac channels, with IC 50 s of 12 μM ( IKr ), 40 μM ( INa ), 8.3 μM ( ICa ), respectively. IDO1-IN-19 has the potential to study cancer diseases.