Since a reduction in retinol and retinol binding protein (RBP) has been found in human newborns with CDH (30, 31), and several key components of the RA pathway are affected in human and experimental CDH (32), the increased activity of the TGFβ pathway might play an important role in the development of the lungs in CDH. Here, TGFB1 is linked to congenital diaphragmatic hernia.