Considering the evidence for both macro- and microscopic abnormalities in the heartof fetuses and children with CDH, we aimed to evaluate the effect of CDH in theendothelial proliferation by evaluating the immunoexpression of Ki-67 (a nuclearprotein used as a marker of cell division) and the endothelial activation bystudying the vascular endothelial growth factor receptor 2 (VEGFR2), an essentialpiece of the angiogenic process and that has been shown to be reduced in the lung ofCDH rabbits (9), and capillary density bylectin staining of intramyocardial vessels. The gene discussed is MKI67; the disease is congenital diaphragmatic hernia.