Triple Negative Breast Cancer cell lines (classified as Mesenchymal-type) and breast cancer cell lines that have undergone EMT express higher levels of GM-CSF and activate macrophages to an M2-like phenotype, suggesting that GM-CSF is necessary to induce M2-like polarization of macrophages16, and thus, that GM-CSF is pro-tumorigenic. This evidence concerns the gene CSF2 and breast carcinoma.