GLRX and chronic myelogenous leukemia, BCR-ABL1 positive: The oxidized glutathione, GSSG, is reduced back to GSH by the glutathione reductase enzyme (GRx) in NADPH presence.49, 50 Furthermore, the evaluation of the vitamin C level showed low level in CML patients, which reinforces the disturbance in the oxidant/antioxidant status observed in these patients.