In addition, studies on the respiratory system have indicated that PM2.5 inhalation increased the levels of proinflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α), demonstrating that PM2.5 is strongly correlated with inflammatory responses in the airway and in patients with COPD [9,10]. The gene discussed is TNF; the disease is chronic obstructive pulmonary disease.