IL13 and newborn respiratory distress syndrome: In our study, when the lung inflammatory response to intratracheal exogenous natural surfactant preparation was evaluated in intubated preterm infants with RDS, as proinflammatory markers IFN-γ decreased significantly, IL-8 increased significantly while no significant changes were observed in the levels of anti-inflammatory markers IL-10 and IL-13 in tracheal aspirate samples examined before and after the application of porcine and bovine lung surfactant.