KIF23 was reported to be overexpressed in pancreatic ductal adenocarcinoma (Gao et al., 2020), malignant pleural mesothelioma (Kato et al., 2016a), lung cancer (Kato et al., 2016b; Ye et al., 2017), breast cancer (Zou et al., 2014), hepatocellular carcinoma (HCC) (Sun et al., 2015; Cheng et al., 2020), gastric cancer (Li X. L. et al., 2019; Liang et al., 2020), and ovarian cancer (Li T. et al., 2019; Hu et al., 2020). This evidence concerns the gene KIF23 and breast cancer.