The different heterozygous mouse models confirmed that the defect in TGFβ signaling due to the haploinsufficiency resembled HHT, as they developed similar vascular abnormalities like telangiectasias, AVMs and endothelial dysplasia (Lowery and de Caestecker, 2010). This evidence concerns the gene TGFB1 and hereditary hemorrhagic telangiectasia.