It is well known that smoking skyrockets the risk of developing lung cancer, but it is hard to understand why some people develop the disease rather quickly while others smoke heavily their entire life and never get it. Now, a new study has highlighted a region of the human genome which may bring about additional risks of developing lung cancer for smokers.

The research was carried out by three teams from France, Iceland and the United States and also linked the genes with nicotine and addiction. "It opens the possibility that treatments that block these genes could be very beneficial as a treatment strategy against lung cancer, as well as against addiction," said Paul Brennan of the International Agency for Research on Cancer in Lyon, France, as quoted by Reuters.

The two variants of the genes, which code nicotinic acetylcholine receptors, exist in about 34 percent of the population and occur in genes in the same region of the long arm of chromosome 15. They alter the effects of nicotine on the human body, triggering responses such as favoring the rapid, uncontrolled growth of cells, which subsequently promotes the growth of new feeder blood vessels, creating, in turn, a particularly hospitable environment for cancer tumors.

"These are very interesting and potentially very, very important findings," says Dr. Norman Edelman, chief medical officer of the American Lung Association, quoted by TIME. "They put nicotine front and center in smoking-related diseases, including lung cancer," Edelman said.

It was previously thought that tar found in smoke was more dangerous than nicotine, but the latest research proves that assumption wrong.

Last week, the research community was under shock when discovering hidden tobacco money behind a big study suggesting that lung scans might help save smokers from cancer. In October 2006, a study by Dr. Claudia I. Henschke and Dr. David F. Yankelevitz, both of Weill Cornell Medical College said annual screening with CT scanners was effective in detecting early lung cancer among smokers and former smokers and so, 80 percent of lung cancer deaths could be prevented.

The Journal of the American Medical Association published the study and noted that it had been financed in part by a little-known charity called the Foundation for Lung Cancer: Early Detection, Prevention & Treatment. Following an investigation by The New York Times, it was discovered that the foundation was underwritten almost entirely by $3.6 million in grants from the parent company of the Liggett Group, (maker of Liggett Select, Eve, Grand Prix, Quest and Pyramid cigarette brands), Vector Group. The money were given in four grants from 2000 to 2003.