TSPO immunohistochemical staining and Tspo-AcGFP formation in the respiratory system. The lung (A–F; b, bronchiole; p, pneumocytes; cce, ciliated columnar epithelium; a, alvolus, ae, type I, II alveolar epithelial cells) and trachea (G, H; cce, ciliated columnar epithelium; sc, seromucinous cells; hc, hyaline cartilage) were examined using H&E staining (A, D, G), TSPO immunostaining (B, E), and AcGFP presence detected by fluorescence microscopy (C, F, H)