CLDN6 and gastric cancer: Recent studies have confirmed that CLDN6 could promote the cell migration and invasion of certain cancers, including breast cancer (Liu Y. et al., 2016; Lu et al., 2017), gastric cancer (Torres-Martinez et al., 2017; Yu et al., 2019), hepatocellular carcinoma (Huang et al., 2020; Kong et al., 2020), and endometrial cancer (Kojima et al., 2021), and can be vigorously stimulated in human-induced pluripotent stem cells developed from fibroblasts, thus might present to be a promising target candidate antibody for cancer therapy (Türeci et al., 2018).