PBK and breast cancer: Previous research has established that TOPK can induce cancer cell proliferation and is highly expressed in numerous types of cancer including lung adenocarcinoma (Lei et al., 2013), ovarian cancer (Ikeda et al., 2016), gastric carcinoma (Ohashi et al., 2017), breast cancer (Park et al., 2006), nasopharyngeal carcinoma (Wang et al., 2016), and colon cancer (Zhu et al., 2007).