In the case of COMP expression in chronic diseases such as pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED), rheumatoid arthritis, systemic sclerosis and pathological would healing (Keloid), it was reported that COMP inhibits normal collagen fibrils formation and destabilize normal extracellular matrix formation in areas where COMP molecules are excessively higher in the relationship to collagen [30], [54]. Here, COMP is linked to pseudoachondroplasia.