IDO1 and neoplasm: The central nervous system permeability of LY3381916 (rodent kp, uu 0.26) is significant. In addition, as an AhR agonist, a number of heme-binding IDO1 inhibitors have been shown to be a substitute for kynurenine. In addition, LY3381916 is shown to potentiate the activity of an anti-PD-L1 antibody (LY3300054) in a preclinical tumor model, which is associated with enhanced T cell responses [126].