PBK and esophageal squamous cell carcinoma: Furthermore, our summary of experimental data confirms that TOPK is notably expressed in bladder cancer, breast cancer, cervical cancer, cholangiocarcinoma, chordoma, colorectal cancer, esophageal squamous cell carcinoma (ESCC), gastric cancer, lung adenocarcinoma, lymphoma, oral cancer, osteosarcoma, and ovarian cancer, whereas it is underexpressed in clear hepatocellular carcinoma (Table 1).