Hypothalamic GCG activated GCGR to stimulate downstream PKA pathway in the hypothalamic ARC, as i.c.v. co-infusion of the GCGR antagonist des-His1-[Glu9] GCG amide or the PKA inhibitor H-89 negated the ability of central GCG to induce anorexia. The gene discussed is GCG; the disease is Anorexia.