Fig. 5
β8 integrin immunohistochemistry (IHC) of MeWo tumor (a), lung (b), and liver tissue (c) of the same animal used for comparative PET scans (Fig. 6). Magnifications in yellow and cyan frames show MeWo areas with low and high cellular β8 integrin expression, respectively. A slight β8 expression is observed in the bronchiolar epithelium of lung (arrows) and alveolar macrophages (arrowheads). No β8 expression in liver tissue. Note that β8 integrin dimerizes only with the ubiquitous αv monomer, which is why β8 is limiting and indicative for actual αvβ8 distribution