SIRT1 and interstitial lung disease: Serum SIRT1 levels were reduced in SSc patients diagnosed with ILD on HRCT scans of the chest (median 0.80 ng/mL, IQR 0.42–1.10 ng/mL) compared to patients without ILD (median 1.19 ng/mL, IQR 0.57–2.24 ng/mL; p = 0.031; Figure 2A).