LCN2 and congenital secretory chloride diarrhea 1: Sveger et al. revealed that preterm infants with respiratory distress syndrome (RDS) showed high expressions of LCN2, human elastase-α1-antitrypsin complex (HEAT) and free and complexed neutrophil protease 4 (NP4), and RDS severity and the risk of developing chronic lung disease of prematurity (CLD) may be correlated with LCN2 expression [14].