At present, the incidence and mortality rate of lung cancer remains high, and with the intensification of population aging and industrialization of cities and towns, as well as the pollution and destruction of human living environment, especially the increasing number of smokers, the incidence and mortality rate of lung cancer in China will continue to climb in the next 20 years. As we all know, there are many causative factors of lung cancer, the main and most important one is smoking, and everyone knows that smoking can cause cancer, but it is an undeniable phenomenon that some people who have smoked for their whole life eventually do not get lung cancer, while some people who have not smoked for their whole life eventually get lung cancer, which makes smokers take a chance. So how do you know if you are prone or not to get cancer? Research has confirmed that the reason for this is that some people’s genes are more “secure” and less likely to be damaged or have a strong ability to repair, while others are not so lucky and are prone to cancer once they encounter carcinogens. People with a family history of lung cancer are such people. Therefore, people with a family history of lung cancer must pay attention to cancer prevention and avoid exposure to carcinogens, especially to stay away from tobacco.