This gene is a member of the sclerostin family and encodes an N-glycosylated, secreted protein with a C-terminal cystine knot-like domain. This protein functions as a bone morphogenetic protein (BMP) antagonist. Specifically, it directly associates with BMPs, prohibiting them from binding their receptors, thereby regulating BMP signaling during cellular proliferation, differentiation, and programmed cell death. [provided by RefSeq, Jul 2008].