TXN and cancer: In addition to its critical role in the regulation of cellular redox homeostasis, thioredoxin has multiple actions in the cell - such as activation of ribonucleotide reductase, inhibition of apoptosis signal regulating kinase 1 and induction of hypoxia inducible factor 1 (HIF-1) and vascular endothelial growth factor (VEGF) - which contribute to many hallmarks of cancer, such as increased proliferation, inhibited apoptosis and angiogenesis [8].