*3.1. Clinicopathological Characteristics*

A total of 425 patients with early stage NSCLC were included in the data analysis without dropout. The mean age of the patients at diagnosis was 61 years (range, 37–82 years), and men accounted for 74% of the cases. Adenocarcinoma and squamous cell carcinoma comprised 46% and 47% of the cases, respectively. Patients at I, II, and IIIA stages accounted for 56%, 43%, and 5%, respectively. The relationship between NME1 expression and clinicopathological characteristics is summarized in Supplementary Table S1. NME1 expression was found to be reduced in 165 (39%) of 425 patients. Reduced NME1 expression was not associated with patient's age, sex, tumor size, or exposure to tobacco smoke. However, reduced NME1 expression was found to have a significantly higher prevalence in squamous cell carcinoma (46%) than in adenocarcinoma (34%), and the difference was statistically significant (*p* = 0.01; Figure 1B).

**Figure 1.** Immunohistochemical staining for non-metastatic cells 1 (NME1) and β-catenin expression in non-small cell lung cancer. (**A**) Expression levels of NME1 and β-catenin were analyzed using immunohistochemical staining (scale bar = 100 μm). Representative images of positive staining are shown in adenocarcinoma (upper) and squamous cell carcinoma (lower) at magnification of ×200. Cytoplasmic staining was considered positive for NME1 and β-catenin expression. (**B**) Prevalence of reduced NME1 expression and β-catenin overexpression was compared according to histologic subtypes. *p-*values were based on Pearson's chi-square test. (**C**) Association between recurrence and the expression levels of NME1 or β-catenin was analyzed in 425 participants.

Postoperative recurrence occurred in 186 (44%) of 425 patients. Patients with reduced NME1 expression had a higher recurrence rate than those without (62% vs. 32%, *p* < 0.0001). β-catenin was overexpressed in 55% of patients, with a higher prevalence in squamous cell carcinoma than that in adenocarcinoma (*p* = 0.005; Figure 1B). Recurrence was found at a high prevalence in patients

with reduced NME1 expression but not β-catenin overexpression irrespective of histologic subtypes (Figure 1C).
