ATP1B4 and Patent ductus arteriosus: Unlike CDA and FDA, relatively weak positive selection signals were found in PDA with only two PSGs (CELA3B and SLC36A1) clearly involved in protein utilization48,49, whereas the other two PSGs (ATP1B3 and ATP1B4), which are involved in both CDA and PDA, play a role in maintaining ionic homeostasis (Fig. 2).