Subject characteristics.

<p>Subject characteristics.</p

Graphs showing epithelial phenotype.

<p>The percentage of epithelium with squamous metaplasia (A), that with a pseudostratified (B) and a fully squamous (C) phenotype are shown in healthy non-smokers (●), healthy smokers (■) and subjects with COPD1(▲) and COPD2(▼). Significant differences between the groups are indicated.</p

Panel of antibodies used.

<p>Panel of antibodies used.</p

Epithelial expression of early markers of carcinogenesis and proliferation.

<p>CEA is expressed in the luminal cells of pseudostratified epithelium (A), p53 is weakly expressed in the perinuclear region of suprabasal cells (B), nuclear expression of ki67 can also be seen (C). Positive staining is brown. No staining was observed in the negative controls sections (D). Scale bar = 20 um. The percentage of the epithelium expressing CEA (E), p53 (F) and Ki67 (G) are shown in healthy non-smokers (●), healthy smokers (■) and subjects with COPD1(▲) and COPD2(▼). Significant differences and Kruskall Wallis P values between the groups are indicated.</p

Epithelial correlations.

<p>Epithelial correlations.</p

Correlations between epithelial phenotype and measures of lung function.

<p>Correlations between epithelial phenotype and measures of lung function.</p