Although CD163+ MØs, CCL2 and CCL7 are associated with cancer metastasis and poor prognosis28–30 and high CCL2 levels are found in various cancer types, including breast cancer and some NSCLC31–33, blocking the CCL2/CCR2 axis alone does not impede tumors from recruiting monocyte-origin resident MØs5. This evidence concerns the gene CCL2 and breast cancer.