CCL2 and neoplasm: The results showed that the experimental 4T1 cells transfected with CCL2 overexpression vectors began to proliferate quickly and exhibited several oncogenic phenomena at day 4, such as invasive ductal structures extending outward, disorganized architectural morphology in the 3D Matrigel, as well as increased number of abnormal grape-like tumor structures (or 3D acinar structures) (Figure 6Fb).