In accordance with previous studies, exposure to cigarette smoke caused elevated in TNF-α and IL-6 gene expression in lung tissue and enhanced levels of these cytokines in the BALF of rats compared to the control group which was correlated with the increase in inflammatory cells in bronchoalveolar lavage fluid, suggesting that increased inflammatory factors production increases COPD severity. This evidence concerns the gene IL6 and chronic obstructive pulmonary disease.