IRF8 and Granuloma: Accordingly, quantitative analysis of tissue damage revealed that, although the numbers of granulomas in the lungs did not significantly differ between mouse strains (data not shown), at day 30 p.i. IRF-8−/− mice exhibited significantly higher median granuloma surface area (Fig. 2E), median total tissue surface area with lesions (Fig. 2F) and area with lesions versus healthy tissue ratio (Fig. 2G) compared to controls.