Others have shown NADPH oxidase (NOX-2) activation, increased vascular ROS formation, higher 3-nitrotyrosine levels, diminished vascular nitric oxide bioavailability, decreased BH4 levels, and eNOS uncoupling by e-cigarette vapor exposure, all of which were associated with endothelial dysfunction and higher blood pressure [23]. The gene discussed is FMO5; the disease is endothelial dysfunction.