Tauber et al. (19) found that BNP levels in preterm infants without PDA increased significantly on the first day after birth, decreased on the fifth day, and remained at a low level thereafter, while gestational age had no significant effect on BNP levels; this study helped to increase the understanding of BNP levels in preterm infants with PDA. The gene discussed is NPPB; the disease is Patent ductus arteriosus.