ROS mediated by CS-induced oxidative stress activates the p38 MAPK and NFκB signaling pathways in both the epithelial cells and the alveolar macrophages of COPD patients and enhances the expression of inflammatory mediators, such as IL8, TNF, and the granulocyte-macrophage colony-stimulating factor [42,43]. The gene discussed is TNF; the disease is chronic obstructive pulmonary disease.