Moreover, several studies have shown that leptin can decrease the function of regulatory T (Treg) cells and increase the percentage of T helper 1 (Th1) cells; these events can, to some extent, explain the reported positive correlation between obesity and TPOAb positivity by stating that as a result of altered immune function, obese individuals are more prone to autoimmune and inflammatory processes in the thyroid gland [40, 41]. Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.