IL15 and obesity due to melanocortin 4 receptor deficiency: Assessing the serum concentrations of IL-15 in patients belonging to the three degrees of obesity and three grades of HS at US, no significant difference was found among the groups (P = 0.06 and P = 0.7, respectively) and also when adjusted for age (P = 0.06 and P = 0.6, respectively).