On the cover: A granuloma from a CD11a KO mouse after aerosol infection with virulent Mycobacterium tuberculosis. Lung tissue was stained with Mason's trichrome stain, and the extensive blue staining indicates fibrosis. CD11a KO mice develop granulomas, but their centers are diffuse and there is a paucity of lymphocytes compared with normal mice. Ghosh, S., A. A. Chackerian, C. M. Parker, C. M. Ballantyne, and S. M. Behar. 2006. The LFA-1 adhesion molecule is required for protective immunity during pulmonary Mycobacterium tuberculosis infection. J. Immunol. 176: 4914–4922.