STC2 is a secreted, homodimeric glycoprotein that is expressed in a wide variety of tissues and may have autocrine or paracrine functions. The protein has 10 of its 15 cysteine residues conserved among stanniocalcin family members and is phosphorylated by casein kinase 2 exclusively on its serine residues. Its C-terminus contains a cluster of histidine residues which may interact with metal ions. The protein may play a role in the regulation of renal and intestinal calcium and phosphate transport, cell metabolism, or cellular calcium/phosphate homeostasis. Expression of this gene is induced by estrogen and altered in some breast cancers. Recombinant human STC2 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.