Several GWAS performed in Asian, European, and African populations identified polymorphisms in the CHRNA5 and CYP2A6 genes strongly associated with the risk of smoking [10], being a heavy smoker (≥20 cigarettes per day) [11], to a better success in the treatment to stop smoking [9] or in the development of diseases caused by cigarette smoking (mainly COPD and lung cancer) [12,13]. The gene discussed is CHRNA5; the disease is lung cancer.