IL6 and obesity due to melanocortin 4 receptor deficiency: Various local or systemic cytokines are increased in obesity, including IL-1α [49, 50], TNF-α [51], leptin [52], and IL-6 [12, 53], while IL-1α, in combination with TNF-α and IL-6, is involved in the pathology of atherosclerosis in obese individuals.