During cerebral ischemia, production of free radicals overwhelm possibility of detoxification and capacity for its removal by enzymes of antioxidative protection like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and nonenzymatic antioxidants (vitamin C and E, glutathione) resulting in fast and severe damage of cellular proteins, lipids and DNA [3], [5]. The gene discussed is CAT; the disease is brain ischemia.