CLDN4 is a crucial member of the tight junction protein, although the role of CLDN4 in carcinogenesis remains controversial [16], many studies have revealed the carcinogenic functions of CLDN4, whose abnormal expression has been shown to contribute to tumor development [30], such as ovarian [15], breast [31], prostate [21], pancreatic [32] and gastric [33] cancers. This evidence concerns the gene CLDN4 and cancer.