This gene product belongs to the glutathione peroxidase family, which functions in the detoxification of hydrogen peroxide. It contains a selenocysteine (Sec) residue at its active site. The selenocysteine is encoded by the UGA codon, which normally signals translation termination. The 3' UTR of Sec-containing genes have a common stem-loop structure, the sec insertion sequence (SECIS), which is necessary for the recognition of UGA as a Sec codon rather than as a stop signal. Knockout studies in mice indicate that mRNA expression and activity of this enzyme are induced by luminal microflora, suggesting a role for this peroxidase in preventing inflammation in the GI tract. [provided by RefSeq, Jul 2008]