●Adhesion articulated. Mould, A. P. & Humphries, M. J. Nature 4 November (2004).

The publication of a crystal structure of an integrin head region complexed with ligand has provided further evidence for a model of integrin activation that involves unbending and vertical extension to mediate cell adhesion.

●Iron and microbial infection. Schaible, U. E. & Kaufmann, S. H. E. Nature Reviews Microbiology December (2004)

Iron is necessary for bacterial survival, but the host also needs iron for the generation of reactive oxygen and nitrogen species in the innate immune response to infection. This shared requirement for iron has had an important role in the evolution of the host–pathogen relationship.

●Gene map of the extended human MHC. Horton, R. et al. Nature Reviews Genetics December (2004)

This article presents the latest gene map of the extended 7.6-Mb MHC region (the xMHC) in humans and analyses its gene composition, evolution and function. This is accompanied by a poster of the human xMHC in the December issue of Nature Reviews Genetics.

●Challenges in bringing the bench to bedside in drug development for SLE. Merrill, J. T., Erkan, D. & Buyon, J. P. Nature Reviews Drug Discovery December (2004)

●The double-stranded-RNA-binding motif: interference and much more. Tian, B., Bevilacqua, P. C., Diegelman-Parente, A. & Mathews, M. B. Nature Reviews Molecular Cell Biology December (2004)

●Lead and follow: the dance of the dendritic cell and T cell. Lanzavecchia, A. & Sallusto, F. Nature Immunology December (2004)

This News and Views article discusses two papers that have visualized resident dendritic cells (DCs) in intact lymph nodes to gain insight into the DC–T-cell interactions that lead to the induction of immunity or tolerance.

●Viral hijacking of G-protein-coupled-receptor signalling networks. Sodhi, A., Montaner, S. & Gutkind, J. S. Nature Reviews Molecular Cell Biology December (2004)

As described in this Review article, viruses can hijack signalling through G-protein-coupled receptors, such as chemokine receptors, to exploit the activation of intracellular pathways that help to propagate the virus and might cause disease.

●Why are rabbits uniquely sensitive to myxoma virus? Cherchez l'interferon! Vilček, J. Nature Immunology December (2004)

Recent research indicates that the remarkable species specificity of myxoma virus is due to the lack of an interferon (IFN) response by permissive cells, which is in contrast to the activation of extracellular signal-regulated kinase 1 (ERK1) and/or ERK2, leading to IFN gene transcription, that occurs in non-permissive cells from other species.