May be involved in the development and regeneration of the musculoskeletal system. Expressed specifically in the musculoskeletal system (skeletal muscle and tendon). Highly expressed during bone regeneration, especially during the early phases (post fracure days 3 and 5). Expression within the fracture callus is localized in osteoprogenitor cells of the periosteum, proliferating chondrocytes, and young active osteoblasts. Abundantly expressed in developing embryos, especially in mesenchymal condensations of limbs, vertebral perichondrium and mesenchymal cells of the intervertebral disks. Belongs to the MUSTANG family.