Consistent with this idea, many antioxidant enzymes that are known to be upregulated after oxidative stress, particularly mitochondrial superoxide dismutase (SOD2), glutamate-cysteine ligase (GCLC) and hemoxygenase 1 (HMOX1), metallothioneins (MTX), gluthathione peroxidase (GPX2), and thioredoxin reductase 1 (TXNRD1), are induced after infection in epithelial cells [32]. Here, TXNRD1 is linked to infection.