Interestingly, acute infusion of glucagon resulted in sustained hyperglycemia as a consequence of stimulated gluconeogenesis and glycogenolysis in the liver (Gastaldelli et al., 2000; Shah et al., 2000), which, however, occurred only in human diabetic subjects with impaired β-cell function, but not in non-diabetic subjects (Rizza et al., 1979). Here, GCG is linked to Hyperglycemia.