Additionally, in breast cancer progression, mediators are produced in the tumor microenvironment, such as the proinflammatory cytokines IL-6, MCP-1, and IL-1β, adipokine leptin, the angiogenic mediator PAI-1, and VEGF, which are involved in cell proliferation, migration, and remodeling of the microenvironment [21]. This evidence concerns the gene CCL2 and breast cancer.