Negative regulator of bone growth that acts through inhibition of Wnt signaling and bone formation. Interacts with LRP4 (via the extracellular domain); the interaction facilitates the inhibition of Wnt signaling. Interacts with LRP5 (via the first two YWTD-EGF repeat domains); the interaction inhibits Wnt-mediated signaling. Interacts with LRP6. Widely expressed at low levels with highest levels in bone, cartilage, kidney, liver, bone marrow and primary osteoblasts differentiated for 21 days. Detected in the subendothelial layer of the aortic intima (at protein level). The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. A 52 kb deletion downstream of SOST results in SOST transcription suppression causing van Buchem disease. The disease is caused by variants affecting the gene represented in this entry. Heterozygous mutations located in the secretion signal of the SOST gene prevent sclerostin secretion and can be responsible for craniodiaphyseal dysplasia. Belongs to the sclerostin family.