OCLN and melanoma: The abnormal expression of specific markers is a typical feature of the EMT process, such as the upregulation of N-cadherin, snail family transcriptional repressor 1 (Snail), Vimentin, Occludin, and fibronectin 1 (FN1) and the downregulation of E-cadherin [13], which ultimately leads to melanoma metastasis [14].