- Targeted deletion of alkylpurine-DNA-N-glycosylase in mice eliminates repair of 1,N6-ethenoadenine and hypoxanthine but not of 3,N4-ethenocytosine or 8-oxoguanine. Hang, B., Singer, B., Margison, G.P., Elder, R.H. Proc. Natl. Acad. Sci. U.S.A. (1997)