For example, most studies that determined whether APE1 can be used as a predictive marker showed that high level expression or cytoplasmic staining were associated with poor outcomes and resistance to chemoradiotherapy in patients with lung cancer, breast cancer, head and neck cancer, osteosarcomas, germ cell tumors and hepatocellular carcinomas [19]. This evidence concerns the gene APEX1 and hepatocellular carcinoma.