MRC1 and breast cancer: By analyzing the expression of macrophage marker (F4/80) and M2-type macrophage marker (CD206) in the IV2 xenograft tumors, we found that compared to the IgG1 control group, tumors with CXCL7 antibody injection displayed significantly reduced number of F4/80 or CD206 positively labeled cells (Fig. 4E, F), demonstrating that CXCL7 could act as an important modulator to promote breast cancer progression through promoting the recruitment of TAMs.