LEP and obesity due to melanocortin 4 receptor deficiency: Obesity is described by enlarged adipose tissue and dyslipidemia resulting in an excessive non-esterified fatty acids (NEFAs) release and the secretion of several biologically active elements, so-called adipokines, including tumor necrotic factor-α (TNF-α) and interleukin-6 (IL-6), leptin, and adiponectin, from the adipose tissue, ultimately promoting systemic low-grade inflammation or meta-inflammation.