COL11A2 encodes collagen type XI alpha 2 chain, a component of type XI collagen.[1] Type XI collagen forms heterotypic collagen fibrils with type II collagen and is expressed in various tissues including articular cartilage and tectorial membrane of the cochlea.[2]COL11A2 knockout mice exhibit small bodies, facial abnormalities, and deafness, as well as disorganized growth plate in long bones. The gene discussed is COL11A2; the disease is deafness.