CLDNs are the main components of TJs, which have barrier and fence functions and maintain cell polarity, cell adhesion, and cell signal transduction [37,38], and dysfunction of TJs was found to be closely related to tumor development, e.g., CLDN6 overexpression inhibited the migration and invasion of MCF-7 cells in vitro [4]. This evidence concerns the gene CLDN6 and neoplasm.