Studies have demonstrated that HupA could enhance the cell viability and the activities of antioxidant enzymes including glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT); decrease the level of malondialdehyde (MDA) in PC12 (neuron-like rat pheochromocytoma) cells and cultured rat primary cortical neurons (Xiao et al., 2000a,b); and markedly reduced the MDA level in chronic cerebral hypo-perfusion rats (Wang et al., 2000) and aged rats (Shang et al., 1999). The gene discussed is CAT; the disease is pheochromocytoma.