IDO1 and neoplasm: Notably, genes mediated by IFN-γ, a key cytokine in the tumor microenvironment were also significantly upregulated in high inflammation (STAT1, CCR5, CXCL9, CXCL10, CXCL11, CCL2, CCL4, CCL5, CCL13, CCL17, CCL18, CCL19, CCL21, CCL22, IDO1, PRF1, IRF4, IRF8, GZMA, HLA-DRA, HLA-DMA, Fig. 3B).