Recent studies demonstrated that TMAO promotes vascular inflammation and oxidative stress, inhibits eNOS expression and activity and reduces NO production, which are associated with endothelial dysfunction and atherosclerosis (Wang et al., 2011; Hu et al., 2015; Chen et al., 2016; Seldin et al., 2016; Sun et al., 2016). This evidence concerns the gene NOS3 and endothelial dysfunction.