IL6 and obesity due to melanocortin 4 receptor deficiency: Several inflammation-related chronic diseases including obesity, cancer, diabetes, and Alzheimer’s disease are necessarily related to an increase in pro-inflammatory effectors including nitric oxide (NO) and various pro-inflammatory cytokines containing tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) [7].