X-chromosome genetics and human cancer. Spatz, A., Borg, C. & Feunteun, J. Nature Reviews Cancer August (2004). This review explores how X-chromosome inactivation influences the outcome of cancer-causing genetic and epigenetic alterations.

Seeing double. Goffeau, A. Nature 1 July (2004) This News and Views article discusses recent studies that highlight the importance of genetic duplication events in the evolution of yeast genomes.

Milestones in development. Nature, Nature Cell Biology, Nature Reviews Neuroscience, Nature Reviews Genetics and Nature Reviews Molecular Cell Biology (July 2004). This supplement highlights the key discoveries in developmental biology over the past 100 years. The topics for the Milestones were chosen with the help of 34 developmental biology experts, and highlight studies that provided insights into specific developmental mechanisms, many of which are conserved across the animal kingdom. The Milestones are available free online for 6 months at http://www.nature.com/milestones/development.

The ins and outs of gene expression control. Perler, F. B. Nature Biotechnology July (2004). Inteins are protein elements capable of self-excision from a precursor protein and ligation of the flanking protein regions. In a recent study described in this News and Views article, temperature-sensitive mutant inteins were inserted into transcription factors, providing a new tool for controlling gene expression in yeast and flies.

Genetic regulation of biological nitrogen fixation. Dixon, R. & Kahn, D. Nature Reviews Microbiology August (2004).

An ongoing genetic battle? Srivastava, D. Nature 24 June (2004) Congenital heart disease causes abnormalities in heart development and cardiac dysfunction in adults. In this News and Views article, Deepak Srivastava discusses recent studies in mice that indicate that the underlying genetic mutation causes these defects through distinct mechanisms.

Neurodegeneration. Nature Medicine and Nature Reviews Neuroscience July (2004) This supplement is a collection of Reviews and Perspectives that provide an authoritative update on the cellular processes that are common to the most frequently observed diseases of the brain, their underlying genetic basis and the approaches that are being pursued to treat these devastating conditions. These articles are available free online for 3 months at http://www.nature.com/focus/neurodegen/.