COMP plays diverse roles including the regulation of collagen secretion and fibrillogenesis, and the proliferation of chondrocytes in cartilage, the enhancement of cellular attachment and the inhibition of thrombin in blood vessels, the resistance to mechanical stress in tendons, the tissue remodeling in systemic sclerosis, or the trigger of the alternate pathway of the complement in the immune system [29,30,31]. Here, COMP is linked to systemic sclerosis.