Compared with neonatal rats exposed to air, BPD neonatal rats exhibited increased levels of inflammatory factors (IL-1β, TNF-ɑ, IL-6, Flt-1 and ICAM-1) (Fig. 3A–D) and an increased number of macrophages (Fig. 3E, Additional file 3: Fig. S2A), and these trends were reversed by miR-214 agomir treatment. Here, IL1B is linked to bronchopulmonary dysplasia.