Collagenase-3 (MMP-13) is expressed by hypertrophic chondrocytes, periosteal cells, and osteoblasts during human fetal bone development. - Johansson,N.; Saarialho-Kere,U.; Airola,K.; Herva,R.; Nissinen,L.; Westermarck,J.; Vuorio,E.; Heino,J.; Kähäri,V-M. (Dev Dyn, 1997)