These variables were subjected to univariate conditional logistic regression analysis, including smoking history, BMI, histopathology types, complications (chronic lung disease, hypertension, diabetes), tumor markers (CEA, CYFRA 21‐1, NSE), treatment‐related characteristics (central venous catheterization, chemotherapy, anti‐vascular, immunotherapy), and ECOG PS score. The gene discussed is ENO2; the disease is neoplasm.