SIM2 and Patent ductus arteriosus: In addition to GATA4 gene expression, the peroxisome proliferator-activated receptor gamma gene (PPARG) (65), the hepatocyte nuclear factor-4-alpha (HNF4A) (66), the hypoxia-inducible factor 3 subunit alpha (HIF3A) (67), the MYB proto-oncogene (MYB) (68), and the single-minded 2 (SIM2) (69) genes were also previously described to be highly expressed in PDA.