PECAM1 and systemic sclerosis: In this context, recent studies showed the presence of cells in intermediate stages of EndoMT in vessels of lung and dermal tissues of patients with SSc (85–87).Furthermore, the treatment of human normal dermal microvascular endothelial cells with TGFβ and SSc sera induced a myofibroblast morphology and the expression of markers of myofroblasts (a-SMA and type I collagen) with downregulation of endothelial markers (CD31, VE-cadherin) (87).