GPX2 and cancer: In addition, many antioxidant enzymes, such as glutathione synthetase (GSS), γ-glutamylcysteine synthetase (GCLC/GCLM), glutathione peroxidase (GPX), thioredoxin reductase (TXNRD), and catalase (CAT), are overexpressed in certain resistant cancer cells and in patients with cancer.33 TCGA database showed a positive correlation between NFS1 expression and GSS, GCLC, GCLM, GPX2, TXNRD3, and CAT expression (Supplementary Fig. S6f).