Although no significant differences in total serum TGF-β1 levels between SSc patients and healthy controls have been observed, serum-active TGF-β1 levels in diffuse cutaneous SSc patients are negatively correlated with skin score and lower than active TGF-β1 levels in limited cutaneous SSc patients and healthy controls [113]. This evidence concerns the gene TGFB1 and systemic sclerosis.