ACTA1 and systemic sclerosis: After co-culture with SSc-ECs: 1) HC-MSCs showed a significant increase of α-SMA and collagen-related genes when compared to their basal levels (α-SMA, P = 0.0002; Col1A1, P = 0.0002; Col1A2, P = 0.0002); 2) SSc-MSCs did not show any difference in the expression of these genes when compared to their basal conditions.