Free energy lights the path toward more effective RNAi. Silva, J. M., Sachidanandam, R. & Hannon, G. J. Nature Genetics December (2003). A News and Views article on recent work that provides validated rules for designing short interfering RNAs.

An eye on organ development. Epstein, J. A. & Neel, B. G. Nature 20 November (2003) The authors of this News and Views article comment on a surprising new way in which cells can fine-tune gene expression, which has consequences for our understanding of organ formation during development.

The human model: a forward genetic dissection of immunity to infection in natural conditions. Casanova, J. -L. & Abel, L. Nature Reviews Immunology January (2004)

Ageing, repetitive genomes and DNA damage. Lieber, M. R. & Karanjawala, Z. E. Nature Reviews Molecular Cell Biology January (2004) An Opinion article on oxidative DNA damage, the loss of genetic information with age and the significance of genome organization.

From polyploidy to aneuploidy, genome instability and cancer. Storchova, Z. & Pellman, D. Nature Reviews Molecular Cell Biology January (2004)

Impact of race/ethnicity on molecular pathways in human cancer. Wienke, J. K. Nature Reviews Cancer January (2004) This Opinion piece looks at the role of race/ethnicity in the nature of genetic and epigenetic alterations that programme the malignant behaviour of the cancer cell.

Challenges of implementing pharmacogenomics in the critical care environment. Freeman, B. D. & McLeod, H. L. Nature Reviews Drug Discovery January (2004) These authors look at the potential of pharmacogenomics in guiding drug selection for acutely ill patients in the critical care environment.

Approaches for the sequence-specific knockdown of mRNA. Scherer, L. J. & Rossi, J. J. Nature Biotechnology December (2003) The authors of this Review discuss the challenges of sequence-specific mRNA knockdown, which need to be met before any antisense molecule can become widely accepted as a therapeutic agent.

The origin of malaria: mixed messages from genetic diversity. Hartl, D. L. Nature Reviews Microbiology January (2004)

Ultrafast DNA sequencing. Kling, J. Nature Biotechnology December (2003) A News Feature on the race to reach the US $1,000 genome.

Two worms are better than one. Blaxter, M. Nature 27 November (2003) A News and Views piece on the recent completion of the Caenorhabditis briggsae genome sequence and its comparison to that of C. elegans.