However, other non-significant relationships between BMI and serum concentrations of IL-2, IL-4, IL-10 and IFN-γ could not be explained that obesity induce no changes in the expression of above cytokines, which might be related to the determination of above cytokines in the local joint tissue-not in the serum. Here, IFNG is linked to obesity due to melanocortin 4 receptor deficiency.