SDC4 and systemic sclerosis: Although the molecular basis for SSc is unclear, we have previously shown that fibroblast from scarred (lesional) area of SSc patients show elevated constitutive extracellular signal-regulated kinase (ERK) activation and overexpress a cohort of profibrotic genes including connective tissue growth factor (CTGF, also known as CCN2), and the heparan sulfate containing proteoglycans (HSPGs) syndecan 2 and syndecan 4 [7,8].