Predicted to be an extracellular matrix structural constituent conferring tensile strength. Predicted to be involved in extracellular matrix organization. Predicted to act upstream of or within cell adhesion. Predicted to be located in extracellular region. Predicted to be part of collagen type IX trimer. Predicted to be active in collagen-containing extracellular matrix and extracellular space. Is expressed in integument; intestine; liver; and thymus. Orthologous to human COL28A1 (collagen type XXVIII alpha 1 chain).