NOS2 and obesity due to melanocortin 4 receptor deficiency: Lipid oxidation products, such as oxidized low-density lipoprotein (oxLDL) and malondialdehyde (MDA), as well as nitric oxide (NO) derived from the inducible nitric oxide synthase (iNOS), are positively correlated with obesity severity (Prazny et al., 1999; Couillard et al., 2005; Weinbrenner et al., 2006; Ctoi et al., 2018).