Prevalence of altered expression of five proteins and their correlation according to smoking status. (A) The expression levels of five proteins were analyzed using immunohistochemical staining. Representative examples of positive staining of the five proteins are shown in adenocarcinoma (upper) and squamous cell carcinoma (lower) (×200). (B) The prevalence of altered expression of individual proteins was compared according to smoking status. P values were based on Kruskal-Wallis test. (C, D) Correlation among the five proteins was analyzed using Spearman’s correlation coefficient in (C) never-smokers and (D) ever-smokers. Magenta color indicates P < 0.05.