NK cells with reduced anti-cancer functions in the immunosuppressive lung tumor microenvironment acquire pro-cancer properties and begin to produce and secrete VEGF and CXCR2 ligands such as CXCL1, CXCL2, and CXCL8/IL-8 as well as IL-6, CCL2, matrix metalloproteinases (MMP), and many others [148]. This evidence concerns the gene CCL2 and cancer.