CAT and cancer: This effect seems to be more relevant on cancer cells, in fact while normal cells take advantage from redundant mechanisms for H2O2 clearing and/or repair of H2O2-induced damage, to counteract the effects of pro-oxidant concentrations of AA; cancer cells lacking of these compensatory mechanisms (e.g., catalase deficiency, mutated DNA repair, and tumor suppressor genes) are more susceptible to pharmacologic ascorbate concentrations [132].