A study of Murakami and coworkers [78] provided evidence that the decreased GSH levels and increased glutathione disulfide (GSSG) levels in the erythrocytes of patients with type 2 diabetics is attributed to the decreased activity of enzymes involved in glutathione metabolism such as glutamate cysteine ligase and glutathione reductase. Here, GSR is linked to type 2 diabetes mellitus.