This gene encodes a member of the chordin family of proteins. Chordin family members are secreted proteins that share a cysteine-rich pro-collagen repeat domain and associate with members of the transforming growth factor beta superfamily. In vitro assays demonstrate a direct interaction between the encoded protein and human activin A. This gene is expressed in many tissues including osteoblasts, where it is differentially expressed during differentiation. In addition, its expression is upregulated in human osteoarthritic joint cartilage, suggesting a role in adult cartilage regeneration. [provided by RefSeq, Jan 2015].