Histopathological analysis of inflammation in the lungs of WT and T-bet-/-mice in response to NiNPs. A) Lung pathology was scored in mice for inflammation 1 and 21 days after initial exposure. All data represent mean values ± SEM. *p < 0.05, ***p < 0.001 compared to the control group of the same genotype (n = 5–7 animals/group). B) Representative photomicrographs at low magnification (10×) of H&E stained lung sections at 21 days after mice were exposed. TB: Terminal bronchiole, ADB: alveolar duct bifurcation, AD: alveolar duct. C) Higher magnification (40× and 100×) of images from 10× in (B).