As we were mainly interested in the vessel changes in the Rbm and since there was no significant difference in percent area of the epithelium stained for TGF-β1 between the “extreme groups” S-COPD and H-N groups [median (range) 6% (0–31) vs. 21% (0–51) respectively, p = 0.3] in the preliminary “scoping” study, no further measurements were performed for the other two groups. The gene discussed is TGFB1; the disease is chronic obstructive pulmonary disease.