Based on the comparison between plasma GSH and catalase in BCC patients and controls, Chaisiriwong et al. [50] found reduced oxidative defenses (reduced catalase and glutathione peroxidase activities in plasma) as well as an increase in a systemic redox marker (urinary 7,8-dihydro-8-oxo-2′-deoxyguanosine) in the cancer group. The gene discussed is CAT; the disease is skin basal cell carcinoma.