IFT88 and familial atrioventricular septal defect: A targeted deletion of Ift88 resulted in a shortening of the distal truncus in the OFT, an apparent hypoplasia of endocardial cushions (ECC), and a reduction in ventricular trabeculation [63], but OFT septation defects and/or AVSD were not examined due to the early death of the embryos.