Additionally, kynurenine binds to the aryl hydrocarbon receptor (AHR) in the tumor-associated macrophages (TAMs) to facilitate expression of multiple immunosuppressors, e.g. ectonucleotidase CD39, which could reduce transcription of proinflammatory factors in CD8+ T cells through adenosine elevation in the GBM microenvironment (11). This evidence concerns the gene ENTPD1 and neoplasm.