WFDC2

WAP four-disulfide core domain protein 2 - also known as Human Epididymis Protein 4 - is a protein that in humans is encoded by the WFDC2 gene.
HE4 is a tumor marker of ovarian cancer, with 80% sensitivity at a cut-off of 150 pmol/L.

Function

This gene encodes a protein that is a member of the WFDC domain family. The WFDC domain, or WAP Signature motif, contains eight cysteines forming four disulfide bonds at the core of the protein, and functions as a protease inhibitor in many family members. This gene is expressed in pulmonary epithelial cells among other tissues, and was also found to be expressed in some ovarian cancers. The encoded protein is a small secretory protein, which may be involved in sperm maturation.