CGA and adrenal gland pheochromocytoma: Serum CgA levels have an 83% to 89% sensitivity in diagnosing PCC,[113] and up to 100% when combined with urinary catecholamines,.[114] High levels of CgA may indicate a greater likelihood of malignancy in PPGL; moreover, CgA levels are also correlated with plasma metanephrine levels, which can be used to predict tumor responses to treatment and recurrence.[115]