TFAP2B and Patent ductus arteriosus: We previously identified several polymorphisms in the genes PTGIS and TFAP2B that were associated with different rates of PDA closure in a population composed primarily of preterm infants with European genetic ancestry.10 These associations were not replicated by other investigators using populations with different or more diverse genetic origins.14,15 In line with these discordant observations, our current study found consistent associations between PTGIS and TFAP2B polymorphisms and the expression of “DA closure genes” in DA with European genetic ancestry.