SIGLEC6, also known as CD327, belongs to the immunoglobulin superfamily, SIGLEC (sialic acid binding Ig-like lectin) family. SIGLEC6 is a sialic acid recognizing protein expressed at high levels in placenta (cyto- and syncytiotrophoblastic cells) and at lower levels in spleen, peripheral blood leukocytes (predominantly B-cells) and small intestine. SIGLEC6 localizes in various compartments such as membrane fraction, extracellular region and so on. SIGLEC6 may show increasing expression human labor and following childbirth, it has been speculated that this expression helps to slow the tempo of human labor. Interestingly, expression of SIGLEC6 is further upregulated in pre-eclampsia, which appears to be a uniquely human disease.

> 90 % as determined by SDS-PAGE.