TXN and cancer: Enzymes involved in the protection against damage from oxidative stress, such as superoxide dismutase (SOD-1), thioredoxin (Trx), and in DNA repair, such as purinic/apyrimidinic endonuclease/redox factor-1 (Ref-1) and 8-oxoguanine glycosylase (OGG) are important natural defenses against cancer development.