Obesity can induce increased c-Jun N-terminal kinase (JNK) activity [44, 45] which is activated in response to inflammatory cytokines, free fatty acids [22], activated NF-κB, and inflammatory mediators, including TNF-α and IL-6, and may contribute to insulin resistance [23, 24]. This evidence concerns the gene IL6 and obesity due to melanocortin 4 receptor deficiency.