TGFB1 and systemic sclerosis: Levels of TGFβ1 measured by ELISA were significantly higher in SSc serum samples (mean ± SD values, 86.55 ± 23.12 pg/mL) than in healthy control serum samples (mean ± SD values, 31.24 ± 17.64 pg/mL; p < 0.001).