Smoking cessation improves health conditions with reduction of the risk factors for cardiovascular and respiratory disease, as functional capacity and quality of life. Smoking cessation has positive effects on the miRNAs regulation, however, genomics has been little explored. Smoking and aging induces changes miRNAs. Among the changes in airway epithelial cells, miR-125 called attention because it is enrolled in the suppression of ERBB7 (tirosin kinase receptors), a codified sequence of the growth factor receptor (EGFR) frequently expressed in cancer. The reduction of miR-125 expression may reduce cancer suppression resulting in cancer development. Other miRNA changes can be observed, such as miR-218 that were found in smokers airway epithelial cells as in MiR-15b that were found in lung tissue of COPD smokers. These miRNAs participated in the signalling pathway of TGF-β enrolled in leukocyte migration and cell proliferation. The investigators hypothesize that smoking cessation has a role in the regulation or reduction in the genetic changes smoking-induced. The investigators will assess the subject genomic profile at the baseline, 6 months and 12 months after smoking cessation.