Fructose 2,6-bisphosphate plays a unique role in regulation of gluconeogenesis in liver. The concentration of the blood glucose is regulated within narrow limits. Since glycolysis and gluconeogenesis share the same pathway but operate in opposite directions, their activities are regulated reciprocally. The pathway of gluconeogenesis in liver and kidney utilises those reactions in glycolysis, which are reversible, plus four additional reactions that circumvent the irreversible non-equilibrium reactions. Glucagon is secreted as a response to hypoglycemia and activates both gluconeogenesis and glucogenolysis in the liver, causing release of glucose into the blood.