S100A4 and systemic sclerosis: The downregulation of the lymphatic endothelial nuclear factor Prox1 and of the cell surface receptor LYVE-1, along with a parallel increase in the myofibroblast markers S100A4, α-SMA, and Snail1 upon treatment of HdLy-MVECs with SSc serum or TGFβ1 was also confirmed by immunofluorescence analysis (Figure 5).