Also, SSc IgG did not affect expression of the collagen genes, col1A1 or colIII in VSMCs after 72 h (data not shown), despite this being the time point at which PDGF and TGF-β caused the greatest modulations in col1A1 or colIII gene expression in these cells (data not shown). This evidence concerns the gene TGFB1 and systemic sclerosis.