Previous studies have shown that a decrease in APE/ref-1 protein renders mammalian cells sensitive to methyl methanesulphonate and hydrogen peroxide (Walker et al, 1994), while radioresistance of human cervical tumours directly correlates with increased APE/ref-1 expression (Herring et al, 1998). The gene discussed is APEX1; the disease is uterine cervix neoplasm.