FMO5 and obesity due to melanocortin 4 receptor deficiency: Moreover, the obesity is characterized by higher oxidative stress behavior, contributing to the development of cardiovascular and metabolic comorbidities; in particular, several studies have found the activation of the main physiological source of reactive oxygen species production, NADPH oxidase (in particular the NOX2 catalytic subunit), favoring the alteration of nitric oxide synthase (NOS) activity and consequent endothelial dysfunction and cardiovascular organ damage (29).