Health

Scientists have known for a while that breast cancer is really four different diseases, with subtypes among them, an insight that has helped improve treatment for some women.

But experts haven't understood much about how these four types differ. A new report, published online in the journal Nature, provides a big leap in that understanding.

A mysterious virus has put a Qatari man in critical condition at a U.K. hospital, the World Health Organization said Sunday.

His illness is due to a new type of coronavirus, the family of viruses that causes common colds and severe acute respiratory syndrome, or SARS.

Researchers have found the first drug to treat progeria, an extremely rare genetic disease that causes children to age so rapidly that many die in their teens.

The drug, called lonafarnib, is not a cure. But in a study published Monday of 28 children, it reversed changes in blood vessels that usually lead to heart attacks and strokes.