TNFRSF11B and chronic kidney disease: Although several biomarkers, such as calcium, phosphate, alkaline phosphatase, parathyroid hormone, fibroblast growth factor–23 (FGF-23), Klotho, vitamin D3, osteoprotegerin (OPG) and sclerostin, play important roles in pathological pathways of CKD-BMD [11–13], the exact pathogenic mechanisms remain unclear and additional factors are likely to be involved.