GSR and pheochromocytoma: In patients with pheochromocytoma, we observed that plasma redox status correlated positively with serum GSH-Px (p = 0.001, R = 0.669), serum GR (p = 0.008, R = 0.576), plasma GSH (p < 0.0001, R = 0.761), and plasma LOOH (p = 0.025, R = 0.501), while it correlated negatively with plasma GSSG (p = 0.015, R = −0.535) and urine normetanephrine (p = 0.023, R = −0.507).