HBB and idiopathic interstitial pneumonia: As shown in Figure 3E and 3F, the Hbα positive areas (Epi+Int and Epi) between the control, COPD and IPF groups differed significantly (Kruskal Wallis test; p = 0.007) while the Hbβ positive areas (Epi+Int and Epi) did not (Figure 3G, 3H).