To further investigate the ability of SSc serum to trigger the Ly-EndMT process, HdLy-MVECs stimulated for 72 h with serum from healthy donors, serum from SSc patients, or TGFβ1 (positive control) were also characterized from a functional point of view by assessing their contractile properties using the collagen gel contraction assay. The gene discussed is TGFB1; the disease is systemic sclerosis.