MIF and respiratory system disorder: There have been few studies on the role of MIF in respiratory diseases such as RDS and BPD.[2,14,15] Previous studies have suggested that MIF could promote lung development, provoke hypoxia-induced lung injury in mice, or be associated with BPD development.[2,14–16] In this study, we found no significant difference in plasma MIF according to RDS (yes: 7494.4 ± 6026.3 vs no: 8073.7 ± 6722.1 pg/mL, P = .954) or BPD (yes: 12,423.7 ± 9615.5 vs no: 7380.7 ± 5942.9 pg/mL, P = .132) among the 25 preterm neonates born at <34 weeks of gestation.