In addition, monocytes polarized to the M2 macrophage phenotype upregulate PD-L1 and elaborate cytokines, such as MCP-3 and CXCL1, which further enhance immune infiltration, the induction of angiogenesis, and the recruitment of myeloid cells into the tumor microenvironment [37, 38]. This evidence concerns the gene CCL7 and neoplasm.