ENG and telangiectasia, hereditary hemorrhagic, type 2: Mutations in ACVRL1 give rise to an autosomal vascular dysplasia called Hereditary Haemorrhagic Telangiectasia type 2 (HHT2) [1], while HHT type 1 is caused by mutations in ENG, the gene coding for the TGF-β co-receptor Endoglin [23].