Exposure of cells to a wide variety of chemoprotective compounds confers resistance to a broad set of carcinogens. For a subset of the chemoprotective compounds, protection is generated by an increase in the abundance of protective enzymes such as glutathione S-transferases (GSTs). We have recently developed a cell culture system that potently responds to the phenolic antioxidants upon induction of GST activity and found that the J 2 series of PGs, 15-deoxy-Δ 1 2 , 1 4 -prostaglandin J 2 (15d-PGJ 2 ) in particular, preferentially induces the synthesis of GSTs. The molecular mechanism underlying the 15d-PGJ 2 -induced GST expression has been elucidated.