Figure 6
From: Variability in the precursor proteins of collagen I and III in different stages of COPD
![Figure 6](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1465-9921-11-165/MediaObjects/12931_2010_1008_Fig6_HTML.jpg)
Precursor protein of collagen III in the large airways of non-smokers, smokers and the patients with COPD. The subepithelial layer expressing precursor protein of collagen III was thicker in all smoker groups compared to non-smokers.