SPARC and systemic sclerosis: Recently, SPARC (secreted protein, acidic and rich in cysteine), a matricellular component of the ECM, has been reported as a bio-marker for fibrosis in multiple fibrotic diseases, such as interstitial pulmonary fibrosis, renal interstitial fibrosis, cirrhosis, atherosclerotic lesions and scleroderma or systemic sclerosis (SSc) [4-9].