FIGURE 6

Immunohistochemical localisation of ACE2 (angiotensin-converting enzyme 2), TMPRSS2, CD147 and GRP78 protein in human lung tissue. Representative samples from a) a healthy nonsmoker with no underlying chronic airway disease, and b) a smoker with COPD. Black outlines: low magnification (12×) of conducting airways with airway epithelium; scale bars 100 μm. Green outlines: high magnification regions (60×) of conducting airway epithelium that are defined in the low magnification images by green squares; scale bars 50 μm. Red outlines: high magnification regions (50×) of lung tissue away from the airway lumen that are defined in the low magnification images by red squares; scale bars 50 μm. H&E: haematoxylin and eosin. Positive immunohistochemical staining is rust/brown. Total number of independent samples analysed was 49–98.