This gene encodes a secreted calcium-binding phosphoprotein that belongs to the small integrin-binding ligand, N-linked glycoprotein (SIBLING) family of proteins. Members of this family are components of the extracellular matrix of bone and dentin and regulate bone mineralization. Deficiency of a similar protein in mouse results in increased bone mass. Mice lacking this gene are resistant to aging-related trabecular bone loss. Alternative splicing results in multiple transcript variants.