SOST and chronic kidney disease: Although the specific role of sclerostin in the development of vascular calcification in patients with PH cannot be drawn from our study, recent experimental data in a CKD mouse model showing aggravated vascular calcification in Sost-/- mice in which the gene encoding sclerostin was knocked out or in mice treated with anti-sclerostin antibody showed the protective role of sclerostin, playing a counterregulatory function to decrease vascular calcification.