Protein blotting showed that the expression levels of NLRP3 (all P < 0.001), Caspase-1 (P < 0.01 at P5 and P < 0.05 at P7), IL-18 (all P < 0.01), Pro-IL-1β (all P < 0.0001), and IL-1β (all P < 0.01) increased in P5 and P7 in the BPD group (Fig. 3c–h). This evidence concerns the gene IL18 and bronchopulmonary dysplasia.