SOD1 and melanoma: The translational potential of enhancing DSF toxicity by gradual H2O2 delivery to tumor cells [38, 39] by small micron-sized glucose oxidase –microspheres as a source of exogenous ROS [51], but avoiding toxicity from Cu overload is supported by data showing that melanoma cells have increased SOD which generates more H2O2 but lower catalase activities, compared to normal human melanocytes [52].