(Wu et al. 2018) Expression of FMO3 is significantly up-regulated in both explanted skin fibroblasts, and in skin biopsies, from patients with SSc (Chadli et al. 2019; Kim et al. 2022; Skaug et al. 2020) Moreover, in a recent study, SSc patients with interstitial lung disease (ILD) and esophageal dysmotility had higher plasma TMAO levels than non-SSc controls. Here, FMO3 is linked to systemic sclerosis.