Study Ties Poor Oral Health to Cancer-Causing Virus

Researchers report a greater risk of the human papillomavirus, HPV, but other experts questioned the study.

Genetic Code Shows Bird Flu In China Spread Between People

Chinese scientists offer the first clear evidence that the H7N9 bird flu virus can be transmitted from human to human. A father, who became sick in March, passed the virus to his daughter. But the risk of transmission is quite low, and the virus still doesn’t appear to pose a global threat.

How Exercise Changes Fat and Muscle Cells

Several striking new studies provide some clarity by showing that exercise seems able to drastically alter how genes operate, perhaps altering the risk for problems like obesity and diabetes.