Compared to patients without BPD or with only mild BPD, preterm infants that eventually developed severe BPD (still requiring positive pressure support or >0.30 FiO2 at 36 weeks corrected gestational age) expressed higher levels of inflammatory genes on day 7, including IFITM2, IRAK3, CCL3, IL1A, and IL1B (Fig. 1g, h). This evidence concerns the gene IL1A and bronchopulmonary dysplasia.