Moreover, expression of immunomodulatory proteins such as PD-1, PD-L1, and indoleamine 2,3-dioxygenase (IDO) by tumor and/or immune cells correlated with the overall spatial architecture of the tissue, leading to distinction between mixed and compartmentalized tumors, with both showing peculiar gene expression, spatial distribution, and prognosis. This evidence concerns the gene IDO1 and neoplasm.