TAM-secreted IFN-γ activates the JAK/STAT3 and PI3K/AKT pathways to increase PD-L1 expression while transforming growth factor beta (TGF-β) polarizes macrophages towards an M2 phenotype, which enhances the suppressive activity of TAMs, upregulates PD-L1 expression and facilitates tumor escape. This evidence concerns the gene CD274 and neoplasm.