Disruption of this equilibrium may lead to metabolic disturbances, insulin and leptin resistance coexist in diabetes, obesity and CVD due to both of them share the same signal transduction pathways such as protein tyrosine phosphatase 1B (PTP1B) and suppressor of cytokine signaling 3 (SOC3) [123, 124]. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.