Some studies have found high levels of oxidative-damage products, including MDA, F2-isoprostanes, and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in serum or saliva of OLP patients, along with impaired antioxidant defences, including low levels or activity of glutathione, catalase, superoxide dismutase, and total antioxidant capacity [3,9,11,17]. The gene discussed is CAT; the disease is oral lichen planus.