CLDN1 and colonic neoplasm: On a broader level, this study complements evidence that adhesion proteins should not be considered simply in terms of their mechanical adhesion properties, since (for instance) overexpression of the tight junction protein Claudin-1 in colon cancer has been shown to promote expression of ZEB1, a transcription factor which represses E-cadherin expression [53] and can, therefore, promote epithelial to mesenchymal transition.