NSG mice occasionally develop macro-metastases when MCF7 cells are injected orthotopically into the mammary fat pad.

<p><b>A.</b> Volumes of tumors in mammary fat pads of NSG mice injected with MCF7 cells. Each data point is the mean value (+/− s.e.m) of 12 primary tumors. <b>B.</b> Micrographs of haematoxylin and eosin (H&E), CK18, EGFR and Her2 IHC staining of harvested MCF7 primary tumor tissue. MCF7 primary tumors are CK18 positive, EGFR negative, Her2 negative. <b>C.</b> Quantification of the percentage of mice bearing macro-metastasis in each organ observed at the time of necropsy (184 days post injection). Macro-metastases were observed in the left axillary lymph node (67% of mice), lung (25% of mice), and spleen (25% of mice), as well as sporadically in other organs. LN = lymph node. <b>D.</b> A photograph of an MCF7 kidney metastasis is shown, along with micrographs of H&E and CK18 IHC staining of harvested tissue.