Lung cancer is more prevalent in the people who are having the chain smoking habit. Also it is observed in the case of passive smokers who are basically non smokers. The Nicotine content that is inhaled while smoking is detrimental and it leads to the infection of lung cancer to greater extent. Hence every nation is trying to ban the smoking in the public places to avoid the incidence of lung cancer. In the recent studies the scientists have found that two new genetic variations are also contributing to the occurrence of lung cancer in the human being.These genetic variations are causing the lung cancer in both the smokers and non smokers.