SMAD2 and systemic sclerosis: In a preclinical mouse model of systemic sclerosis, FG-3019 treatment reduced skin fibrosis and cellular expression of a number of fibrogenic related proteins, including platelet-derived growth factor receptor beta (PDGF-β), procollagen, αSMA, phosphorylated Smad2, and fibroblast specific growth factor 1 when provided 3 times weekly using intraperitoneal injections, for two weeks, to CCN2/CTGF knock out mice [31].