Furthermore, the percentage of total vessels in the Rbm staining for TGF-β1 was significantly different between groups (Kruskal-Wallis test, p<0.05), with S-N, S-COPD and ES-COPD having a higher percentage than the control group [median (range) for S-N 31% (0–121), for S-COPD 40% (0–123) and for ES-COPD 22% (0–114) vs. H-N 0 (0–26)] (Figure 3). This evidence concerns the gene TGFB1 and chronic obstructive pulmonary disease.