TGFB1 and systemic sclerosis: Indeed, while HdLy-MVECs at basal condition or after treatment with healthy serum presented mainly with a cortical actin cytoskeleton organization (i.e., actin fibers arranged at the cell periphery), those challenged with SSc serum or TGFβ1 underwent a profound rearrangement of their cytoskeleton, with actin assembling into longitudinal stress fibers, which are characteristic of myofibroblasts (Figure 2).