PDGFRA and systemic sclerosis: Elevated expression of PDGF and its receptors has been found in SSc skin and lung tissues and there is evidence that TGF-β stimulates the expression of the PDGF receptor, PDGFRα, in SSc cells suggesting that cross-talk between TGF-β and PDGF pathways may regulate tissue fibrosis in SSc (180) and it has been suggested that PDGF/PDGF receptor may represent a novel molecular target for SSc (182).