Figure 2.

Top, left to right: Masson trichrome-stained sections of large airway tissue from healthy control (A), asthma-COPD overlap (B), and asthma (C). Bottom, left to right: COPD current smokers (COPD-CS) (D), COPD exsmokers (COPD-ES) (E), and normal lung function smokers (NLFS) (F). Images are representative of tissues obtained from healthy control, NLFS, and pathological groups in ×40 magnification. Nuclei and muscle: magenta; RBM and collagen: blue; RBC: orange. Note thickened RBM, increased goblet cells, hypocellularity in asthma-COPD overlap airways. COPD, chronic obstructive pulmonary disease; Ep, epithelium; G, goblet cells; RBM, reticular basement membrane; MV, microvessels. *RBM cell. Scale bar, 50 µm.