It is worth noting that mRNA expression levels of other antioxidative enzymes, namely peroxiredoxin 1 (Prdx1), glutathione peroxidase (Gpx), but not superoxide dismutase 1 (Sod1), were similarly higher in the PMA type of tumor tissue than in healthy parotid tissue (Figure 6J–L). This evidence concerns the gene SOD1 and neoplasm.