NOS3 and endothelial dysfunction: Another marker of endothelial dysfunction is the inability of acetylcholine to induce endothelium-dependent relaxation in vessel preparations in vitro (Balarini et al., 2013) and this was also induced by TNFα (Wang et al., 1994) since it reduces endothelial nitric oxide synthase (eNOS) expression and activity (Steyers and Miller, 2014).