– GSTK1 gene encodes a member of the kappa class of the glutathione transferase superfamily of enzymes that function in cellular detoxification. Glutathione S-transferases (GSTs) are a family of enzymes that catalyze a variety of reactions in both eukaryotes and prokaryotes. They catalyze the conjugation of reduced glutathione with potentially toxic, xenobiotic substrates, thus aiding excretion from the body. GSTK1(glutathione S-transferase kappa 1) is localized to the peroxisome and catalyzes the conjugation of glutathione to a wide range of hydrophobic substates facilitating the removal of these compounds from cells. GSTK1 functions in cellular detoxification.