CCL2 and neoplasm: In the models in which human MDA-MB-231 cells were orthotopically injected or MDA-MB-231-derived 4173 cells were injected via the tail vein into SCID mice, either anti-human CCL2 antibody (Ab) or anti-mouse CCL2 Ab significantly inhibited lung metastasis, suggesting that the infiltration of IMs was dependent on CCL2 synthesized by both tumor and stromal cells.