The levels of proinflammatory cytokines, such as TNF-α, IL-1β, IL-6, and IL-8, are increased, and the levels of anti-inflammatory cytokines, such as IL-4, IL-10, IL-12, IL-13, and IL-18, are decreased in BPD (26, 27). This evidence concerns the gene IL18 and bronchopulmonary dysplasia.