This gene encodes a chondrocyte-specific, highly charged protein that is abundantly expressed in the upper immature zone of fetal and juvenile epiphyseal cartilage. The encoded protein undergoes proteolytic processing to generate a mature protein that is secreted into the extracellular matrix. The glutamic acid residues in the encoded protein undergo gamma carboxylation in a vitamin K-dependent manner. Undercarboxylation of the encoded protein is associated with osteoarthritis in humans. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2015].