Glutathione S-transferase (GST) represents a major group of detoxification enzymes. It acts by catalyzing the reaction of glutathione with an acceptor molecule to form an S-substituted glutathione (S=sulfur). The reactions utilizing glutathione contribute to the transformation of a wide range of compounds, including carcinogens, therapeutic drugs, and products of oxidative stress. Apart from its enzymatic activities, GST may also bind toxins and function as a transport protein.