The development of new research tools can often add impetus to a slow-moving area of research. The concept of synthetic lethality — that the mutation of two genes individually does not kill a cell, but mutation of both of these genes does — was first mooted by Stephen Friend and Lee Hartwell in 1997. In a review on page 689, William Kaelin discusses how the availability of RNA interference technology to perturb gene function, together with the ability to perform large-scale genomic screens, has allowed synthetic lethal genes to be identified and exploited to discover new targets for anticancer drug development.

Established models in cell culture monolayers or soft-agar assays do not recapitulate the structural organization or functional differentiation of glandular epithelium in vivo. Another new tool — 3D epithelial culture systems — is proving valuable for modelling cancer genes in epithelial cancers in a structurally relevant context. This model is discussed, using breast cancer as an example, by Jayanta Debnath and Joan Brugge on page 675.

This month we also launch a Web Focus on Cancer vaccines, which is freely available online (htpp://www.nature.com/reviews/focus/cancervaccines) until February 2006. One of the reviews in the Focus also illustrates how a struggling field can be re-energized by new techniques. In the review (first published as Laheru, D. & Jaffee, E. Nature Rev. Cancer 5, 459–467 (2005)), the authors explain how new screening techniques are unveiling immunogenic antigens in pancreatic cancer that might be of use in developing immunotherapy for this hard-to-treat tumour. The discovery of a relevant pancreatic cancer animal model will also help to test new vaccine strategies more efficiently and rapidly. The Web Focus also contains many other Reviews, Perspectives and Highlights (from Nature Reviews Cancer) that relate to cancer vaccines.