APE-1 may be a useful target for modifying radiation tolerance: the inhibitors lucanthone and CRT004876 were employed, the former a thioxanthene previously under clinical evaluation as a radiosensitizer for brain tumors and the latter a more specific inhibitor (Naidu et al., 2010); knockdown of APE-1 gene expression may significantly sensitize pancreatic cancer cells to radiotherapy (Chen et al., 2013). The gene discussed is APEX1; the disease is brain neoplasm.