Functional Characterization of Circulating Tumor Cells (CTCs) from Metastatic ER+/HER2− Breast Cancer Reveals Dependence on HER2 and FOXM1 for Endocrine Therapy Resistance and Tumor Cell Survival: Implications for Treatment of ER+/HER2− Breast Cancer. The gene discussed is FOXM1; the disease is breast carcinoma.