Given this context, the objective of this current study was to quantify components of the HHT signaling pathway, including VEGFA, TGFβ1, ANG2, and ENG, in patients with HHT and in controls, to analyze their diagnostic capacity and usefulness as disease severity markers in our population of patients with HHT. This evidence concerns the gene TGFB1 and hereditary hemorrhagic telangiectasia.