Similar to RON loss in this model [16], mammary tumors from PyMT mice with a loss of HGFL show increases in the recruitment of F4/80+ macrophages with increased M1 macrophages marked by iNOS+ staining and a reduction in M2 macrophages marked by Arginase-1+ staining (Figure 1F). The gene discussed is MST1R; the disease is breast cancer.