CGA and Hypocalcemia: CgA is co‐stored and co‐released with catecholamines from storage granules in the adrenal medulla, or with the parathyroid hormone in response to hypocalcemia in the parathyroid gland.1 Previous studies have confirmed that CgA correlated with norepinephrine release rate when they compared CgA concentration and neurotransmitters concentrations.2, 3 As CgA is much more stable than catecholamines in the circulatory system, its plasma level reflects the sympathetic tone and adrenomedullary system activity.