The tumor was biopsied via bronchoscopy and found to be a poorly differentiated carcinoma, which was strongly positive for cytokeratin 7 (CK7), carcinoembryonic antigen (CEA), and thyroid transcription factor-1 (TTF-1) but negative for CK20, estrogen receptor, and progesterone receptor. The gene discussed is ESR1; the disease is neoplasm.