Independently of the cancer serum used, excised xenotransplants displayed features of adenocarcinomas (H&E staining) with high proliferation index for tumor arising from Fibro-BKO cells (80–93% Ki67 positivity), and moderate proliferation index for tumor arising from MCF-PKO cells (20–45% Ki67 positive cells). The gene discussed is MKI67; the disease is adenocarcinoma.