Obesity is also linked to an inflammatory state, and it seems that the relationship between adipose tissue and thyroid tumorigenesis is related to the adipocytes' ability to produce immunomodulatory molecules, such as increase of tumor necrosis factor alpha (TNFα) with concomitant state of TNFα resistance and increase in interleukin-6 (IL-6) and leptin levels [31]. Here, TNF is linked to obesity due to melanocortin 4 receptor deficiency.