EGFR and metastatic malignant neoplasm in the lymph nodes: Then, we evaluated the correlation between the baseline characteristics of the patients and the expression of AKR1C1 and found that the initial expression of AKR1C1 had no correlation with age, gender, TNM stage, tumor invasion, lymph node metastasis, EGFR mutation subtype or the type of EGFR-TKI they received (supplementary Table S4).