CCL2 and neoplasm: In contrast, the strong tumor promoting effects of fibroblast CCL2 was associated with different effects on the tumor microenvironment, as we found significant decreases in both angiogenesis and recruitment of innate immune cell upon silencing of CCL2. CCL8 had weaker effects on tumor growth than the other tested chemokines, which likely reflects it inability to affect either tumor proliferation or vascularity (Table 3).