These rhythmic processes are compromised in the course of obesity and type 2 diabetes (T2D) development, indicating impairment of the functions (deregulation of signaling and metabolic pathways) of interstitial cells of Cajal, vascular, and pancreatic α, β, and δ cells, which is manifested as diabetic gastropathy, hypertension and atherosclerosis, and insulin and glucagon resistance, respectively [21,25,26,27,28]. The gene discussed is GCG; the disease is type 2 diabetes mellitus.