Glutathione transferases (GSTs) are a family of enzymes that catalyze the conjugation of the tripeptide glutathione to a variety of electrophilic compounds, including drugs, carcinogens, and environmental toxins. This reaction is an important part of phase II metabolism, which is responsible for the detoxification and elimination of xenobiotics from the body. GSTs are expressed in a variety of tissues, including the liver, kidney, and lung.