Sclerostin, the product of the SOST gene, located on chromosome 17, locus q11.2 in humans, was originally believed to be a non-classical Bone morphogenetic protein (BMP) antagonist.More recently Sclerostin has been identified as binding to LRP5/6 receptors and inhibiting the Wnt signalling pathway .Wnt activation under these circumstances is antagonistic to bone formation. Although the underlying mechanisms are unclear, it is believed that the antagonism of BMP-induced bone formation by sclerostin is mediated by Wnt signalling, but not BMP signalling pathways.