TGFB1 and systemic sclerosis: Besides TGF-β, the most important growth factor, involved in SSc tissue fibrosis and in EndoMT, other growth factors and profibrogenic molecules, including platelet derived growth factors [167], vascular endothelial growth factor [168], and insulin-derived growth factor [169], may also participate in EndoMT although their role in this process has not been studied to our knowledge.