GPX1 and kidney oncocytoma: For example, mitochondria-localized glutathione peroxidase 1 (GPX1, 3-fold) and superoxide dismutase 2 (SOD2, 6-fold) were up-regulated in renal oncocytomas, whereas cytoplasmic glutathione S-transferase P (GSTP1, 2.3-fold), glutathione peroxidase 3 (GPX3, 8-fold), superoxide dismutase (SOD1, 2-fold), and extracellular superoxide dismutase (SOD3, 35-fold) were down-regulated (Figure 3A and 3B, Supplementary Table 8).