Additionally, BMP9 is extensively involved in the pathogenesis of many diseases, including hereditary hemorrhagic telangiectasia,24 organ fibrosis,25 idio pathicpulmonary arterial hypertension,26 and malignant cancers.27, 28, 29, 30 Notably, recent studies have highlighted BMP9's potential to induce osteogenic differentiation of MSCs, even surpassing the efficacy of BMP2 and BMP7.31, 32, 33, 34, 35, 36, 37 Moreover, when combined with other growth factors such as IGF2, Leptin, and Wnt11, BMP9 exhibited more robust promoting effects on the osteogenic differentiation of MSCs. Here, GDF2 is linked to hereditary hemorrhagic telangiectasia.