Role of tartrate-resistant acid phosphatase (TRAP) in long bone development

► We examined the role of the TRAP enzyme during endochondral bone formation in mice. ► TRAP does not impair vascularization as well as ossification of the long bone epiphysis. ► TRAP−/− mice show an expansion of the cartilaginous growth plate. ► This malformation is first detected at week three and during further development. ► TRAP appears to be critical for the formation of the metaphysis but not of the epiphysis.