OCLN and neoplasm: An important step in tumor metastasis is EMT in which tumor cells lose their adherent characteristics of epithelial cells with decreasing expression of epithelial markers like E-cadherin and occludins, and acquire a mesenchymal phenotype with migratory and invasive capabilities, overexpressing mesenchymal markers like vimentin, N-cadherin o ß-catenin [98].