Furthermore, evaluation of IL-1β expression, a pro-inflammatory cytokine known to play an important role in BPD pathogenesis [34, 35], demonstrated that the protein expression of this cytokine was significantly increased in lung homogenates obtained from hyperoxia-PL animals (RA vs hyperoxia-PL; P < 0.05, N = 5/group). Here, IL1B is linked to bronchopulmonary dysplasia.