As far as SSc cutaneous subsets are concerned, serum SIRT1 levels in patients with lcSSc (median 1.15 ng/mL, IQR 0.60–2.21 ng/mL) and dcSSc (median 0.77 ng/mL, IQR 0.47–1.06 ng/mL) were both significantly lower than in healthy individuals (p = 0.027 and p < 0.001, respectively; Figure 1A). This evidence concerns the gene SIRT1 and systemic sclerosis.