Figure 1

Epithelial phenotype in smokers (S) and ex-smokers with COPD. Individual values of: (A) % PAS/AB⁺ area of intact epithelium, (B) Ki-67⁺ cells (/mm basement membrane = BSM) in intact epithelium, (C) % squamous cell metaplasia (SCM) of intact epithelium (note: in a large % of patients no SCM was observed), (D) % EGFR⁺ area of intact epithelium. Data are grouped by COPD smokers (S), COPD ex-smokers who quit < 3.5 years ago (<3.5 yr), and who quit ≥3.5 years ago (≥3.5 yr). Horizontal bars represent median values, * p < 0.05.