Tobacco use genetics is one of the best studied among the addictive disorders. The medical importance to the research community is obvious owing to the well-known increases in risk for cancer, cardiac disease, and many other systemic illnesses associated with nicotine, and it is so important medically that tobacco use information is collected in most investigations of medical traits. Furthermore, tobacco use is highly prevalent, resulting in much useful information that can be obtained even from population-based studies. There have been numerous well-powered studies related to tobacco use; we focus here on the largest and most powerful such studies.
