CCL2 and ductal breast carcinoma in situ: CCL2 may also act on CCR2 expressing endothelial cells to promote angiogenesis or macrophages to induce macrophage recruitment and M2 polarization.75,78 Overall, CCL2 and HGF may regulate DCIS progression through complex interactions between cancer cells and the microenvironment and interactions among stromal cells and immune cells.