Three years since the first draft of the human genome sequence was published in Nature, the research agenda for human genomicists has considerably moved on. The HapMap Project is one important endeavour that can be seen as a direct successor to the Human Genome Project, both in terms of its collaborative 'big science' approach and the mixed reaction that it has provoked.

The HapMap Project's potential ethical implications have been one contentious area that has prevented it from being universally applauded. In fact, ethical considerations were high on the list of priorities of the HapMap Consortium when they developed their project plan, as they discuss in this month's Perspective section (page 467). Indeed, the collaborations between geneticists, social scientists and ethicists in this project could provide a model for intergrating ethical and societal considerations into similar large-scale endeavours in the future.

Another question that provoked debate on the merits of the HapMap Project was whether its projected benefits justified its cost. Probably the easiest way for the Consortium to deal with criticisms of this sort is to reduce the costs involved. A recent paper discussed in this month's Highlights section (page 411) shows how technical advances in randomly assembled microarrays should help to achieve this aim.

While the HapMap Project is focussed on collecting a large amount of new data, there is still much work to be done in annotating the largely complete human genome sequence that we already have. This is an important goal of comparative genomics and, as Dario Boffelli and colleagues discuss in their Review article (page 456), it turns out that the comparisons with sequences from the vertebrate phylogenetic extremes relative to humans might be an extremely useful source of annotations.