To dissect the role of TRAIL in the pathogenesis of BPD in the preterm infant we performed an observational study in a prospective cohort of preterm infants (<29 weeks of gestation), and determined the levels of TRAIL in tracheal aspirates of n = 69 infants which required intubation and mechanical ventilation at birth with the expected predominance of male gender (n = 45). This evidence concerns the gene TNFSF10 and bronchopulmonary dysplasia.