SIRT1 and systemic sclerosis: No significant difference in SIRT1 levels was detected when SSc patients were stratified according to the presence of DUs (Figure 3A), whereas SIRT1 was significantly higher in SSc patients with “early” NVC (median 1.41 ng/mL, IQR 0.59–3.08 ng/mL) than in those with “active/late” NVC (median 0.82 ng/mL, IQR 0.46–1.18 ng/mL) patterns (p = 0.014; Figure 3B).