Since CCL2 is also known by the alias monocyte chemoattractant protein-1 and activates macrophages, inactivation of cancer cells by the inhibition of the CCL2–CCR2 axis are partly presumed to be caused by the reduction of tumor-associated macrophages (TAMs) at the primary and metastatic site, inducing the destruction of the immunosuppressive tumor microenvironment and the susceptibility to the antitumor T lymphocyte response. This evidence concerns the gene CCL2 and neoplasm.