POSTN and fibrous dysplasia: It is known that periostin has a functional role as a matricellular protein in a variety of tissue remodeling and wound repair situations[32], and it has been recently confirmed that periostin is a novel marker of intramembranous ossification, but not endochondral ossification, and exhibits upregulated expression in the fibrous component of fibrous dysplasia, due to its prominent influence on collagen fibrillogenesis[33].