IL1B and bronchopulmonary dysplasia: IL-1 is a key pathophysiological culprit in this process; it is highly associated with adverse outcomes in clinical cohorts (17–19), and its pathogenic role has been confirmed in a variety of clinically relevant models of BPD and BPD-PH in neonatal mice, piglets and rats, as reviewed in (20, 21), and in a model of inflammation-induced dWMI in fetal sheep (1, 22).