These monocytes produced MMP-9 in response to the HGF derived tumor stromal.66 Macrophages that support metastatic of cancer cells express surface markers like VEGFR1, CCR2, and CX3CR1, which different from angiogenic macrophages express molecules (such as TIE2 or CXCR4).11 Recent studies demonstrated that CCR2 trigger the production of CCL3 from macrophages in breast cancer mouse model. Here, CCL3 is linked to breast cancer.