CYP2A6 polymorphism consists of alleles with variable structures, ranging from deleted alleles (CYP2A6∗2A/CYP2∗4A) to fully functioning alleles (CYP2A6∗1A), which determine the role that their level of enzymatic activity plays in nicotine etiology and the impact they have on nicotine dependence treatment [1, 2]. The gene discussed is CYP2A6; the disease is nicotine dependence.