CYBB and endothelial dysfunction: -E-cigarette vapor exposure reduced FMD (p = 0.017).-E-cigarette vapor exposure (with nicotine) for 1, 3, and 5 days caused endothelial dysfunction determined by acetylcholine-dependent relaxation in wild-type mice upon all exposure protocols-E-cigarette smoking increased the ROS-producing enzyme NOX-2 (p < 0.01).