TNF and obesity due to melanocortin 4 receptor deficiency: Obesity causes lipid accumulation in adipocytes, which activates c-Jun N-terminal kinase (JNK) and nuclear factor-kappa B (NF-κB) signaling pathways and might subsequently increase the production of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) [11, 19].