CCL2 and neoplasm: Here we have added an additional group in which the CCR2−/− mice that were implanted with the Luc+ CCR2+ tumor cells (C1-TRAMP) were subsequently injected (beginning 25 days after tumor injection, every 5 days, 300 μg/mouse) with a soluble CCR2-Ig receptor that effectively and selectively neutralizes only CCL2 [20].