- DNA repair methyltransferase (Mgmt) knockout mice are sensitive to the lethal effects of chemotherapeutic alkylating agents. Glassner, B.J., Weeda, G., Allan, J.M., Broekhof, J.L., Carls, N.H., Donker, I., Engelward, B.P., Hampson, R.J., Hersmus, R., Hickman, M.J., Roth, R.B., Warren, H.B., Wu, M.M., Hoeijmakers, J.H., Samson, L.D. Mutagenesis (1999)