In colorectal cancer (CRC) studies, Claudin-23 expression was found to be epigenetically regulated and the significant downregulation of claudin-23 expression in tissues was attributed to the occupation of the claudin-23 gene, which encodes a structural component of cell-cell adhesion, by the Enhancer of zeste 2 (EZH2) and significant silencing in CRC tissues. This evidence concerns the gene CLDN23 and colorectal cancer.