Platelet-specific Ido1^−/− mice had increased thrombi in their lungs after infection compared with WT infected mice. (A) Fibrinogen was stained and quantified on day 7 and 10 lung sections to detect thrombi. Images were taken at ×40 original magnification, scale bar represents 50 μm, and (B) immunohistochemistry quantification with ImageJ. (C) Lung sections were immunostained for CD42c on day 7 and 10 after infection to detect thrombi. Images were taken at ×40 original magnification, scale bar represents 25 μm. (D-E) Quantification of (D) thrombi <10 μm or (E) >10 μm averaged over 5 fields per mouse. Data presented as mean ± SEM (∗P < .05, ∗∗P < .01, ∗∗∗P < .001). Data were analyzed using unpaired 2-tailed Student t test.