This gene is a member of a gene family that encodes gamma-glutamyl transpeptidase enzymes. This enzyme consists of a heavy and a light chain, and is able to hydrolyze the gamma-glutamyl moiety of glutathione. It converts leukotriene C4 to leukotriene D4, however, it doesn't convert synthetic substrates that are commonly used to assay gamma-glutamyl transpeptidase. Three transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]