TGFBR1 and hereditary hemorrhagic telangiectasia: Moreover, mutations in several genes of the TGFβ signaling pathway, e.g., ALK1, ALK5, ENG, SMAD4, and TGFBR1/2, are known to cause Marfan or Loeys-Dietz syndrome, both frequently associated with vascular pathologies such as intracerebral hemorrhages or hemorrhagic hereditary telangiectasia [244,299,300,301,302].