TNF and obesity due to melanocortin 4 receptor deficiency: Obesity is characterized by excess body fat, adipose tissue dysregulation, chronic elevations of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-a), leptin, interleukin 1 beta (IL-1B), and interleukin 6 (IL-6), and increased c-Jun N-terminal kinase (JNK) signaling, which often coincides with T2D (Hirosumi et al., 2002).