IL6 and obesity due to melanocortin 4 receptor deficiency: It was reported that obesity would increase concentrations of circulating estrogen since the adipose tissue is a production source of estrogen, especially in postmenopausal patients [34] and for the activity of aromatase that can in turn convert androstenedione to estrone and testosterone to estradiol is strongly stimulated by both interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a), which are usually plentiful within the adipose tissue [34, 35].