INS and obesity due to melanocortin 4 receptor deficiency: Through its action on glutamate receptors and the release of neurotransmitters, it can play an important role in the emergence of pathological processes, the most documented of which is the onset of obesity (by altering the action of leptin, increasing palatability, insulin resistance, release of pro-inflammatory mediators), neurotoxicity (Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, epilepsy, multiple sclerosis, and brain tumors) and reproductive system damage (oxidative stress and protein and DNA changes) [69,70].