APEX1 and cancer: A shift to greater cytoplasmic localization is present in some cancers; mounting evidence indicates that may be prognostic.160, 191, 197, 271, 272 The reason for this abnormal subcellular trafficking is yet unknown; perhaps post-translational modifications drive the protein’s redistribution or a general increase in Ref-1/APE1 levels result in a net cytoplasmic increase.