Following exposure to irradiation and oxidative stress, tumour cells showed elevated APE/ref-1 protein levels (Herring et al, 1998; Ramana et al, 1998; Silber et al, 2002), while overexpression of APE/ref-1 in testicular cancer resulted in bleomycin resistance (Robertson et al, 2001). The gene discussed is APEX1; the disease is testicular cancer.