Within the cancer research field of “DNA repair targeted therapy”, several promising drugs have emerged, particularly targeting poly [ADP-ribose] polymerase 1 (PARP1), and to a lesser extent O6-methyltransferase, ataxia telangiectasia mutated (ATM)/ DNA-dependent protein kinase (DNA-PK), and human apurinic/apyrimidinic endonuclease 1 (APE1) [5,7,17,18]. The gene discussed is APEX1; the disease is cancer.