PDGFRB and systemic sclerosis: Another potent tyrosine kinase inhibitor representing a potential SSc disease-modifying agent is nintedanib, which is capable of simultaneously targeting PDGFR, FGFR, VEGFR and several non-receptor tyrosine kinases including c-Abl, Src, MAPK and extracellular signal-regulated kinase (ERK) [122].