- Enhanced sensitivity and long-term G2 arrest in hydrogen peroxide-treated Ku80-null cells are unrelated to DNA repair defects. Arrington, E.D., Caldwell, M.C., Kumaravel, T.S., Lohani, A., Joshi, A., Evans, M.K., Chen, H.T., Nussenzweig, A., Holbrook, N.J., Gorospe, M. Free Radic. Biol. Med. (2000)