MCP-1 was expressed in similar amounts in the bone marrow of all conditions examined: tumor-bearing mice injected with either MDA-MB-231GFP/Luc2 cells plus EO-231 cells (~ 35% of cells), MDA-MB-231GFP/Luc2 cells plus MC3T3-E1 cells (~ 39% of cells), or MDA-MB-231GFP/Luc2 cells alone (~ 32% of cells) (Fig. 4). Here, CCL2 is linked to neoplasm.