SOD2 and cancer: As mitochondrial MnSOD dismutases the superoxide anion (O2−) into H2O2, any decrease in activity in MnSOD tends to increase O2− and decrease H2O2 (Equation (1) below), with varying and contrasting effects depending on cancer type and stage of the disease.(1)O2−→MnSODH2O2→CAT & CPXH2O