LYVE1 and breast cancer: A total of 7.5 × 104 EO771 mammary tumor cells were orthotopically implanted into the mammary fat pads of recipient C57BL/6 mice and mammary tumors were harvested at sizes of 0.5 and 1.5 cm3, representing early- and late-stage tumors, and LYVE-1+ macrophages were evaluated by flow cytometry (Fig. 2B).