INS and obesity due to melanocortin 4 receptor deficiency: Namely, obesity-associated chronic low-grade systemic inflammation is a typical feature of NAFLD, increasing the levels of inflammatory cytokines, such as IL-6 and tumor necrosis factor-alpha (TNF-α) as the most studied, which may contribute to systemic inflammatory state and influence insulin signaling pathways, thus leading to a consequent insulin-resistant state.