DJ-1 seems to act primarily as a redox-sensitive chaperone and sensor for imbalanced cellular redox state, since its overexpression is induced by a variety of oxidative agents such as paraquat, lipopolysaccharide (LPS), iron, hydrogen peroxide (H2O2), 6-hydroxydopamine, ultraviolet irradiation, and high glucose, protecting multiple kinds of cells including endothelial cells, macrophages, fibroblast cells, neurons, cancer cells, and islet β cells (11, 21–25). The gene discussed is PARK7; the disease is cancer.