By contrast, MMP3 was expressed in ~ 25% of cells in the bone marrow of tumor-bearing mice injected with MDA-MB-231GFP/Luc2 cells plus MC3T3-E1 cells and in ~ 12% of cells in the bone marrow of tumor-bearing mice injected with MDA-MB-231GFP/Luc2 cells plus EO-231 cells (Fig. 4). Here, MMP3 is linked to neoplasm.