Accordingly, we show that stimulation of insulin secretion by the injection of glucose enhances DGC-insulin receptor association and accumulation on the plasma membrane (Fig. 3b, c), whereas reduced signaling through the insulin receptor, as occurs during fasting or diabetes, leads to a fall in the membrane content of these protein assemblies (Figs. 4, 6, and Supplementary Fig. 7a). This evidence concerns the gene INSR and diabetes mellitus.