While exogenous kynurenine is capable of subverting the proinflammatory phenotype of naïve T-cells and immature DC in mice via the AHR [36, 37], we have recently demonstrated that kynurenine is produced by human gliomas in concentrations sufficient to enhance clonogenic survival and motility of tumor cells in an AHR-dependent fashion [25]. The gene discussed is AHR; the disease is glioma.