Supporting this, an enhanced tumor burden, as measured by the percentage of GFP+tumor cells vs. total bone marrow cells, was found in mice received both 5TGM1-GFP cells and myeloma-associated Gr-1+/CD11b+cells compared to those received 5TGM1-GFP cells alone (Fig. 5A, 79.5±2.5% vs. 68.4±6.7% in the bone marrow and 38.2±6.9% vs. 20.3±2.8% in the spleen, respectively). The gene discussed is ITGAM; the disease is plasma cell myeloma.