The epithelial phenotype of cancer cells is governed by claudin-1 (CLDN1), claudin-7 (CLDN7), and E-cadherin (CDH1) genes, while the mesenchymal phenotype is regulated by ZEB1, SNAI1, SNAI2, and Vimentin (VIM) genes [10,38]. This evidence concerns the gene CLDN1 and cancer.