TGFβ family signaling mutations in familial bAVMs are detected in the autosomal dominant disease hereditary hemorrhagic telangiectasia (HHT), which affects roughly 1 in 5,000 people and is characterized by AVM formation and hemorrhage in multiple organs, including the brain, lungs, liver, and/or gastrointestinal tract (Barbosa Do Prado et al., 2019). Here, TGFB1 is linked to hereditary hemorrhagic telangiectasia.