Our data demonstrated that exposure of mice to e-cigarette vapor for up to 5 days led to substantial endothelial dysfunction, cardio-/cerebrovascular ROS formation, eNOS uncoupling, higher activity of the phagocytic NADPH oxidase (NOX-2), exacerbated endothelin-1 expression, as well as adduct formation of acrolein with proteins [47]. This evidence concerns the gene FMO5 and endothelial dysfunction.