The vast majority of cancers are caused not by inherited defects in people’s genes, but by environmental and behavioral factors such as chemical pollutants, this according to the largest cancer study ever to enter the “nature versus nurture” debate. The Washington Post quotes Paul Lichtenstein, head of the Karolinska Institute study in Stockholm, who said environmental factors are more important than gene factors, and that’s important to remember, especially since everyone thinks that everything is solved now that we have the human genome in our computers.

Scientists have long recognized that environmental factors play a notable causal role in many cancers. People from rural Asia, where breast and colon cancers are rare, gradually grow more likely to get those diseases after moving to the United States, the result of mostly unidentified environmental factors.