A genetic study done by Ke Xu and Boyang Li revealed that there are 99 genetic variants that are linked to the start of a smoking addiction and 19 variants that are linked to being able to quit smoking. The study was done of a wide variety of individuals from different backgrounds, and it was done over a long period of time so the researchers could get longitudinal data on the smoking history of the patients. The likelihood of smoking is not entirely genetic, environmental factors also play a role in this trait. About 40-50% of the likelihood of smoking is genetic while the rest is environmental. Xu states that the smoking has decreased by education of policies that raised taxes of tobacco products and limited the sales and advertisement of those products. Also the development of smoking limited zones played a role in decreasing the likelihood of people developing a smoking addiction. The findings of the research are not yet certain, they believe that these genetics variations may only be loosely connected to the patient's smoking behavior, but regardless I think this is a step forward in being able to find a cure for an addiction to smoking. By finding out that genes are involved in addiction can lead to more studies being done for this topic. Once they discover how the decision-making aspects of a smoker's brain is different from an average person's brain, treatments could be developed to help with that. This can also apply to other types of addiction and more people can be alleviated of their disease.