DM is associated with increased levels of Ang II [26–30] and numerous studies have shown that Ang II upsurges production of O2− by activating NADPH oxidases [31–34] in VSMCs [35–37], adventitial fibroblasts [32, 38], ECs [33, 39], and cardiomyocytes [34]. Here, FMO5 is linked to diabetes mellitus.