These genes can be categorized in five groups, which include: immunosuppressive cytokines (IL10 and TGFβ), immunosuppressive Tregs and myeloid populations (FOXP3, CCR2, CSF1R, CSF2/GMCSF, and CXCL12), nutrient depleting and redox enzymes (IDO, ARG1, and NOS2/iNOS), T cell inhibitory ligands and receptors (CD274/PD-L1, Pdcd1lg2/PD-L2, CTLA4, and HAVCR2/TIM3), and tumor vasculature and extracellular matrix elements (VEGFA, AXL, FN1/fibronectin, and Col1a1/collagen). This evidence concerns the gene IDO1 and neoplasm.