Univariate analysis showed that the prognostic factors for survival were age (p = 0.027), pathological stage of CRC (p = 0.019), prior extrathoracic metastasis (p = 0.005), preoperative carcinoembryonic antigen level (p = 0.020), number of pulmonary metastases (p = 0.011), and disease‐free interval (p = 0.026). The gene discussed is CEACAM5; the disease is colorectal carcinoma.