Comparative H&E and Ki67 stainings of axillary lymph node and lung sections from metastasis-bearing mice in the 4T1 + RAW264.7 versus 4T1 inoculation group corroborated the ex vivo bioluminescence imaging results with enhanced metastatic tumor burden and tumor cell proliferation in the 4T1 + RAW264.7 inoculation group (Fig. 3c). The gene discussed is MKI67; the disease is neoplasm.