More extensive sequencing of the H1N1 virus responsible for the current swine flu pandemic confirms a previous study showing that it is a triple reassortment virus, and that its closest relatives have been circulating undetected in swine populations for about 10 years.

A technique has been developed for turning stem cells with male chromosomes into reproductive germline cells and prompt them to divide into sperm.

The swine flu virus may cause more severe symptoms than the usual strains of seasonal flu, but there is disagreement on how infectious it is.

Higher dosages may not be better for a new generation of drugs that are intended to treat cancer, which has implications on how small clinical trials are designed.