APEX1 and prostate intraepithelial neoplasia: Furthermore, the role of APE1 as a potential early diagnostic biomarker for prostate cancer was concluded in a study that demonstrated, with IHC, an increase in both nuclear and cytoplasmic APE1 expression in prostate cancer and prostatic intraepithelial neoplasia (PIN) compared with benign hypertrophy (BPH) [33].