On the cover: Mutation of IFN-γ in the mdx mouse model of Duchenne muscular dystrophy shifts macrophages toward an M2 phenotype and reduces damage, increases regeneration, and improves function of muscle. The image shows a section of IFN-γ null mdx muscle where M2 macrophages (red) are enriched in endomysium between regenerative muscle fibers. Villalta, S. A., B. Deng, C. Rinaldi, M. Wehling-Henricks, and J. G. Tidball. 2011. IFN-γ promotes muscle damage in the mdx mouse model of Duchenne muscular dystrophy by suppressing M2 macrophage activation and inhibiting muscle cell proliferation. J. Immunol. 187: 5419–5428.