Despite the fact that insulin stimulates lipogenesis and inhibits lipolysis via activating the PI3K/Akt/mTORC pathway under normal circumstances, it has been reported that in insulin-resistant states of obesity and type 2 diabetes, hepatic lipid production is increased in concert with increased hepatic glucose production, which indicate that lipogenesis persists in IR as well 71, 72. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.