SOST and chronic kidney disease: While the circulating sclerostin produced in the bone might indeed delay the progression of vascular calcification, the calcified vasculature could itself be a major source of sclerostin alongside the bone as the disease progresses, which could explain the positive association between the two; (4) as a corollary, the role of the Wnt inhibitors during progression of CKD could be different from their role in the healthy population, which would explain the variable results in nondialyzed versus dialyzed population.