Stanniocalcin (originally named hypocalcin or teleocalcin or parathyrin) is a family of hormones which regulate calcium and phosphate balance in the body. The first stanniocanlcin discovered was from fish and was identified as the principal calcium reducing (hypocalcaemic) factor. It was isolated from the special organ of fish called corpuscles of Stannius, hence, the name stanniocalcin. Chemically stanniocalcins are glycosylated proteins (i.e. proteins containing carbohydrate, or glycoproteins) having a molecular mass of 50 kDa. They exist in molecular pairs (homodimers) and are joined together by disulfide linkage. They are made up of about 250 amino acids.