Researchers said Wednesday they have found a genetic link that could explain why some people get stomach cancer when they are infected with a common bacterium. They said their findings could show that stomach cancers are the result of an overreaction of the immune system against infection by the Helicobacter pylori bacterium, which infests billions of people.
"Half the world has got it," said Dr. Emad El-Omar of the National Cancer Institute, who led the study.
