CarcinogenCarcinogens are chemical substances that modify genome of cells to promote cancer transformation. Generally, the term refers to agents that have been introduced by human means, but may be used to refer to any substance tending to cause cancer. DDT, benzene, kepone, EDB, and Asbestos have all been classified as carcinogenic. Tobacco has also been identified as a rich source of hundreds of carcinogens like 1,2-benzo(a)pyrene. Even traditional foods such as bracken (in Japan) are sometimes found to be carcinogenic. Recent reports have implicated Acrylamide in fried foods as a carcinogen. Carcinogens are also often, but not necessarily, mutagens or teratogens.