“…GPx has a single seleno-cysteine residue, which is essential for activity and is present in the five isoforms so far identified (Arthur, 2000;El-Far et al, 2005;Hamanishi et al, 2004). GPx1 is cytosolic (cGPx) and is produced in all tissues, although mainly in erythrocytes, kidney and liver (Zotova et al, 2004). GPx2 is also cytosolic and found in the liver and the colon.…”