The WAP-type four-disulfide core (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 members of the WFDC domain family. This gene encodes a protein which contains a WFDC domain, and is thus a member of the WFDC domain family. This gene and several other gene family members are clustered at 20q13.12. [provided by RefSeq, Jul 2008].