There were no statistically significant differences (p > 0.05) in serum level of FGF-23 [20.31 ± 5.95 pg/ml versus 17.9 ± 6.75 pg/ml], Klotho [5.01 ± 0.97 pg/ml versus 5.11 ± 0.83 pg/ml] and NGAL [20.19 ± 2.35 pg/ml versus 21.31 ± 2.8 pg/ml] between SSc patients with DUs and SSc patients without DUs (Fig. 2A-C). This evidence concerns the gene KL and systemic sclerosis.