S100A4 and systemic sclerosis: Moreover, in parallel experiments SSc serum-treated ADSC not only exhibited a reduced expression of the adipocytic markers perilipin and adiponectin together with a significant upregulation of mesenchymal/myofibroblast markers, such as α-SMA+ stress fibers, S100A4 and type I collagen, but also functionally acquired a myofibroblast-like contractile phenotype.