SOD2 and papilloma: Using the DMBA (7,12-dimethylbenz[a]-anthracene)/TPA (12-O-tetradecanoylphorbol-13-acetate) treatment regimen for tumor initiation and promotion, this laboratory found that overexpression of MnSOD reduces the incidence and number of papillomas per animal compared to non-transgenic mice by inhibiting TPA-induced oxidative stress [319].