Nature v. Nuture

“More than 60 percent of U.S. cancer deaths are caused by smoking and diet. But what about the rest?” asks Scientific American. New studies are seeking the environmental causes of cancer. “But scientists most likely will never be able to tease out the true role of environmental contaminants because environmental exposures, genetics and lifestyle seem to all intertwine. ‘It’s like looking at strands of a spider web and deciding which one is important.'”