POMC and obesity due to melanocortin 4 receptor deficiency: In a study by Donaho et al, plasma concentrations of α-MSH were significantly and positively correlated with BMI only among obese individuals.39 Although the exact underlying mechanisms of these associations are not fully understood, prior studies have indicated that Ag-RP increases the ability of IL-1β to enhance adrenocorticotropic hormone (ACTH), suggesting the possible pro-inflammatory role of Ag-RP and development of obesity and type 2 diabetes.37,40,41 The current study had some limitations.