CLDN1 and esophageal cancer: In addition, we also found that after the cells were induced into drug-resistant esophageal cancer cells by PTX, the expression of EMT-related transcription factor β-catenin was up-regulated, the expression of epithelial biomarkers Claudin-1, ZO-1 and E-cadherin was reduced and the mesenchymal biomarkers N-cadherin, Vimentin expression increased.