KCNJ2 and obesity due to melanocortin 4 receptor deficiency: Because hepatic Kir2.1 expression is able to prevent the hyperinsulinemia and insulin resistance in obesity (Figures 3D and 3L) but does not affect the decrease in hepatic slice aspartate release (Figure 4J), this suggests that a decreased excitatory signal at the HVAN in obesity is not responsible for the development of insulin resistance.